Hat Trick and Lotus Fist offer different things. I think Hat Tricks works a bit better for a more zoning oriented/cautious spacing mixup game. (I haven't messed wit Hat Tricks too much but that's just at a glance; that and throw setups.) My problem with it is that even though EX hat is plus, Lao loses alot of damage with that variation and I always want the threat of high damage.
I don't play like that though, I go in hard and have honestly been stomping pretty much anyone I face so far in sets with Lotus Fist. Confirming off of Orbiting hat, especially to fill gaps when they try to punish has been really useful, not to mention just general pressure with whiffed divekicks on hard knockdowns to close distance etc.