Actually, around 32% or the crit he has is very good, it gives good burst in the spec and optimal DPS in what I've seen from many, many sents/mara's, your dots are going to be your main source of dmg, and higher crits the better imo, you already have 6% extra force crit for them (if specced correctly ) and 15% extra crit chance to dots from juyo form, now what is that? well that is 53% crit chance for your dots, and with them critting 2k and 1.5k then is what makes the DPS high.
I've spent hours and hours parsing on the dummy with my marauder, 30% crit 37% crit etc etc, but 32% somehow shows the best results lol, but then again, it's all about preference Like I go 40% crit on my Sorcerer for healing when others go 30% crit chance, some like to crit more often than others.