Brassman and Nem870 - I have reread the thread, (hey that rhymes) and there has been a lot of good information posted - even though much was opinions, those are valuable as well.
DawgFvr makes a good point as well - availability coupled with marketing. I went to 4 different gun shops in my area. The closest thing I came to a 158 was MagTec 158 FMJ. Sure, I could probably order some, but they are cost prohibitive. Still, if there were a box on the shelf, I'd likely buy em and try em. I do not reload and for the immediate future won't - maybe some day.
When deciding on which round to carry, I do rely at least a little on what's available to me, (immediately). I also mix in a lot of trial and error, (mostly trial) coupled with research. Up until my 642, I have been carrying a .45ACP in some form, for the last 8-years. For many of those years, I carried Black Talons and pretty much ignored any thoughts on ever switching. I had what I felt was a "superior round" for
me. It wasn't until I bought my ParaOrdinance 6.45, that I started to really look at what I was carrying for ammunition. I had been carrying the Talons for years and years and ceremoniously shot the 40-rounds I had been hanging onto for so long. It felt good to let go and open my mind up a bit...
Knowing I'm rambling now, (sorry), I'll get to the end of it. I shot many, many boxes - at great cost I might add, of every defense round I could get my hands on - from mild to wild. I also did a fair amount of research, (technical coupled with opinion) and found the Remington Golden Sabre 185 JHP's were the ticket... Was I carrying a "superior round"? Perhaps, but that didn't really matter. I was carrying what felt best to me - with the full knowledge that even if there were better rounds out there, I still would not want to take a hit from a Golden Sabre.
I arrived at the Speer 135 +P GDHP's in much the same manner. I shot a lot of everything. I must have fired 10 different rounds in the first week of my 642CT ownership. My decision to carry the 135's came from a lot of reading, a lot of shooting and zero marketing. I also factored in cost. With many FFL's jumping on the "Hype-Train" and marking up self defense rounds into the stratosphere, (especially around here), finding 1,000 rounds of 135's for $240.00 delivered was too good to pass up. Pulling some empty boxes out of my car - representing 4 dealers here is my area was telling: Federal HydraShoks 20 rounds - $18.95, Speer GDHP 125's 20 rounds $19.95, Cor-Bon 125's 20 rounds $21.95...Winchester 125 JHP, (the best value of all four) $19.95 50 rounds. The list goes on, but illustrates that marketing may begin with the ammo companies, but ends with many, (not all) FFL's "marking up the hype"...
Truth is, I don't honestly know if my Speer 135 +P GDHP's are "superior" to the FBI loads. What I do know is they work for me, are a handfull, (big bark) and I would not want to be on the receiving end of either of them...