Here is my take. The set of questions you get really determine what "hard" is to you. I find the real GMAT questions very tricky, more so than GMATPrep.
Agree and agree.
On the second point, when I took the gmat, I found myself changing my answer about 3-4 times, because when I re-read the problem, I noticed the "trick." On gmatprep, I never did so.
I certainly ain't no heavyweight - until 6 months ago I had no idea what the GMAT is, and kevin certainly is a veteran. I do agree there are some GMATPrep questions (just a few) that are probably harder than anything the real GMAT will throw at you. However, judging the entire Quant section collectively I still think the real thing is tougher.
It makes sense that it has gotten tougher, right? The GMATPrep software was written a couple of years ago.
Not necessarily. The percentiles have changed, but not the scores. Therefore, one would think the test has remained the same and the caliber of test takers has gotten better.