Ascended armor question
Only pants has an actual increase in the crit dmg % when compared to exotics.
Victory or Death [VoD] – Yak’s Bend
At the very least, go for Knight’s instead of Sentinel. You’ll have plenty of HP from guard stacks, as you said. You’ll be trading vitality for precision, which gets you a lot more crit, while still having good power and toughness.
As far as specific items go, zerk is generally better on hands/feet/shoulders, and other stats on head/chest/legs (you get relatively less crit per stat on those).
EDIT: haven’t checked the numbers on Ascended stuff, so that may have changed.
You literally don’t get an increase in crit dmg % unless you get berserker pants (and that one only increases from 3% to 4%).
Google “dulfy GW2”: they have a breakdown of exotic stats vs ascended stats per piece.
(wasn’t sure if putting links is okay here, so I opt’ed not to. Hope you can find it alright)
Victory or Death [VoD] – Yak’s Bend
If you craft a full set of ascended berserker armor the total increase in stats would only be .
+14 power
+11 precision
+1% crit damage
http://dulfy.net/2013/12/12/gw2-ascended-armor-stats/ has the comparison for all armor sets