I can't offer any definitive information, just personal opionions ... but I own a CS45 and I've handled and shot a G36 upon occasion.
I happen to prefer the grip profile and overall shape of the CS45, and further prefer the flat CS45 magazine baseplates, versus the slightly extended CS45 baseplates with the curved finger rest. The G36 is okay, but it feels more like a slightly resilient 2X4 that's been ripped just a little thinner in one dimension.
Of course, I also happen to prefer the TDA trigger of the CS series, but that's another issue. I can shoot either the Safe Action (constant double action) Glock, or the S&W DA/SA (TDA), with equal results. But then I train with both ... and I've spent the last 15 years training quite a bit on TDA S&W pistols.
I could certainly see how someone's preference for one of the actions over the other would influence their decision, though. Different strokes, and all that.
They both produced reasonably acceptably accuracy for me.
I think they're both small enough that potential owners should carefully consider that they're buying a large caliber pistol built on a reduced size platform ... with all that this involves. Reduced slide mass and increased slide velocities may create some potential functioning issues for some folks, depending on their grip technique, and their choice of ammunition ... especially if they use +P ammunition. And then there's the frame flexion of the G36 to possibly consider ... depending.
Personally, I wouldn't use +P ammunition in either of them, simply because I don't feel that any potential increase in velocity offers
me enough "performance advantage" to offset the potential disadvantages ... increased slide velocity, increased muzzle blast, increased perceived recoil and controllability issues, increased cost ... things of that nature.
My CS45 doesn't "like" Speer 200gr +P. The slide moves so fast that it can sometimes apparently "outrun" the magazine spring for the last round, resulting in a feeding failure where the round wasn't released fast enough, or lifted under the lips fast enough, for proper feeding "timing". I've also had a couple instances where the last round was completely dislodged from the magazine lips, under recoil, and exited the pistol unfired, along with the empty, fired case. I've watched this happen with other, larger framed .45's when using some +P ammunition, too.
I've seen a failure to feed, apparently related to increased slide velocity, occur to someone else shooting 185gr +P in another CS45. I've also had this happen with a Ruger P-90, and watched it happen with more than one G30 using the same 200gr Gold Dot +P, too ... I just dislike +P ammuniiton in smaller .45's ... Other folks may feel differently, and that's fine.
The CS45 does have a little shorter barrel, though ... 3.25" versus the 3.78" of the G36 (which is more the length of the larger S&W 457 or 4513TSW, at 3.75"). The octagonal barrel profile of the G36 might offer some slightly faster velocities than the conventially cut rifling of the CS45.
On that topic, you could also probably favorably compare the G36 to the S&W 457S, since the overall length of the G36 is 6.77" (slide) and the overall length of the 457S is only 7.25" ... and the CS45 has a length of 6.5". That would give the 457S a 1-round magazine capacity advantage (7+1 total capacity), while the CS45 is similar to the G36 at 6+1 rounds total capacity. The G36 is lighter than either the CS45 or the 457S, by approx 3+-8+ ounces, though. Take your pick.
Going back to the subject of +P ammunition, however, I should mention that my 4513TSW ... which also has a 3.75" barrel, like the 457S, but a slightly longer overall length of 7.75" ... doesn't seem to mind the +P 200gr loads as much as the CS45. I can only think of one time it bobbled on one. Of course, it also weighs more and uses the same double-recoil springs as the 4013TSW.
Both the G36 & the CS45 models apparently experienced some magazine problems when they were first released, and both are supposed to have been resolved rather quickly.
In the case of the CS45, I was told that it only affected a small number of early magazines, and was related to the additional magazine body "dimples". The "dimpled" indentations are located at the bottom/rear of the magazine's "P Lips", which are the primary, larger & shallower indentations used on S&W .45 ACP magazines. The additional, smaller & deeper indentations were intended to help prevent the top round from being diplaced forward during the violent recoil of the smaller CS platform. Some of the early indentations were apparently slightly unevenly impressed in the magazine's sides, which caused the rising round to be slightly delayed in it's "timing" as it wiggled from one side to the other passing by the uneven indentations, instead of straight upward between two evenly placed indentations. This was resolved with a change in the manufacturing process.
I know a few folks that really like their CS45's. I'm one of them, by the way. I only know one fellow that owns a G36, and last I heard he was trying to sell it. He said he wasn't confident in it's reliability, since it had exhibited erratic functioning for him. Of course, he also said that he'd taken it to another agency's Glock armorer (I wasn't one at that time), who told him that the pistol was insufficiently lubricated. Apparently it functioned fine for the other armorer after being lubricated, but the owner had lost confidence in it. (This same G36 functioned fine when I handled and shot it once, briefly, using 230gr FMJ. I haven't seen it since he complained about it's functioning).
Can't blame the pistol for the owner's actions ... but try convincing most owners of that.
I've seen more than my fair share of absolutely bone dry, very dirty pistols that were carried daily in holsters without having been properly cleaned & lubed in who knows how long. It always "amazes" the shooter of a pistol that won't reliably function during a qualification session ... because it's completely dry, and often VERY dirty ... when I simply take the pistol and add a couple drops of oil ... and the dirty pistol functions just fine for the rest of the session. And this puzzles them???
Okay, enough babbling ... Sorry.
I guess that I'd have to say that I wouldn't necessarily recommend either a G36 or a CS45 to anyone "new" to shooting .45 pistols. Smaller, diminutive .45's often require a bit more training, knowledge and experience shooting .45's ... than owning other smaller calibers, or larger .45's. I couldn't tell by your posting if you're an old hand at owning & shooting .45 's, or if you're "new" to them.
I'd be more likely to recommend either a G30 or a 457S/4513TSW to a fairly new, prospective .45 pistol owner/shooter ... and even to some more experienced ones. The G30 & 457S are a bit more "user friendly" because of their slightly larger size, grip profile and weight.
Otherwise, I think the G36 & CS45 are both great little .45's.
You really need to shoot both pistols, using QUALITY factory ammunition, at a range somewhere.
Just my thoughts ...
Edited because I can't spell well anymore. Damned word processors. :banghead: