Okay, time to sort out this DEX thing. During beta I decided to put this one to bed once and for all, I've just not got around to dicing up the parses and putting it in a presentable format before.
So, during beta for TSS I levelled to 71 then parked myself in the Arena for a few days while I went to work (or out to the wolf centre on Sunday).
I cast Rabid Bear on myself and used my Grokui's Clawed Hammer, auged with a CS 4 aug, then ran a 768 minute parse against a L70 mob. I then repeated the test with an extra 90 DEX courtesy of Ancestral Aid, to see if DEX over the cap made any difference. The second test was only 568 minutes long, but that's still nearly ten hours.
For the first test I had 370 DEX, for the second I had 460 DEX. I also had a Cleave II item, which should give a 4% base rate to crit.
And the results were:
Without Ancestral Aid
Freezing Strike IV: 1536 procs, 2.01 procs per minute (PPM)
Chaotic Strike IV: 1519 procs, 1.99 PPM
Diseased Bite: 3999 procs, 5.23 PPM
Melee crits: 4.1%
With Ancestral Aid:
Freezing Strike IV: 1143 procs, 2.01 PPM
Chaotic Strike IV: 1071 procs, 1.89 PPM
Diseased Bite: 2889 procs, 5.08 PPM
Melee crits: 4.4%
So there you go - DEX does nothing above 365 as suspected. If I'd got around to analysing that in beta I'd have feedback'd to have the DEX overcap changed to a proc modifier instead on Focus and on Ancestral Aid - doh!
It also appears melee crits increase with DEX, as has been mooted on other boards.
For what it's worth, YALP says my crushing melee sustained 62.7 DPS without Ancestral Aid and compared wiith 63 DPS with Ancestral Aid. Looks like that extra 90 STR over the cap's doing a lot too....
For the purists, you can access the logs at
http://www.medvale.net/temp/Logs.zip