I bought these two combined (from AIM) for less than my next most expensive rifle.
The design is remarkably simple and robust. There really isn't a whole lot of bad to say about them, considering the price:
The good:
-They're simple and robust; easy to clean; bolt is easy to disassemble.
-They're $70
and come with a whole host of accessories: ammo pouches, slings, bayonets, oil bottles, cleaning tools, and the "Mosin tool" which acts as a screwdriver, bolt assembly tool and firing pin protrusion checker.
-They work almost without fail (note: neither of mine has ever misfired or jammed, but no mechanical device is infallible and ammo quality does play a role as well).
-Ammo is very cheap by today's standards (approx. 15 cents/round).
-Sights are easier to read than a lot of comparable milsurp rifles.
-They're a lot of fun.
The bad:
-They're heavy and ergonomics leave something to be desired - the triggers in "stock" form are awful and the shape of the buttstock isn't as comfortable or intuitive as that of the K31 or K98k. Also, the M44 is noticeably front-heavy.
-Accuracy is passable but not great. All else being equal, the 91/30 should be the more accurate between the two (particularly in my case - 91/30 has a sharper, cleaner bore with an undamaged, intact crown). You could conceivably get one that's impossibly frustrating to use, but the arsenal refinished examples seem to be alright. Do note that some people have accurized their 91/30s with very pleasant results (i.e. close to MOA).
-Recoil becomes downright painful after a while if you aren't using a recoil pad or shield - I say this as a fit 23 year old male. Rest assured that if you aren't wearing the above (or a Russian winter coat), you probably won't be blasting away all day at the range the way you would with a 5.56 or something.
Really, though, since all of the "bad" stuff actually adds to the character of the design, who's to complain? Buy one.
I bought both of my rifles sight unseen, as noted. The M44 (1944 Izhevsk) has a very pretty stock and probably would have won a "handpick" selection had it not ended up in my hands by chance, though the bore has seen some use (still very functional). The 91/30 (1942 Izhevsk) has an uglier finish and some obvious handling damage to said finish, but a very nice bore. Both of them are completely matching (not force-matched/renumbered/electropenciled).