I'm experiencing this too...
Ive been running redNAND for weeks with zero issues, switched over to Mocha 0.1 and again, zero issues but since updating to 0.2 its been really unstable.
When I first updated yesterday Mocha booted up fine and I even played a game for a few hours, shut down my console to get food, came back, booted Mocha and it froze during boot up. I left it for 2 hours but it never loaded. Spent a few hours messing with it but decided to give up and start again today.
Today I started by formatting my USB drive with my redNAND games on then removing it from my Wii U. Next I formatted my SD Card then reinstalled HBL & Mocha onto it, launched Mocha and let it redump my nand which finished about an hour ago. During the last hour Mocha has crashed 4 times, twice in Mario Maker, once in HBL and once in HBAS.
Nothing has changed with my setup, I've changed no settings on the Wii U or in Mocha.
I'm guessing its a regression in 0.2 and hopefully will be resolved in 0.3.
That's not true at all. Running CBHC poses a real brick risk to your console while running Mocha in sysNAND mode does not.
Running CBHC & Mocha together in sysNAND mode is pointless but running Mocha in sysNAND mode instead of CBHC eliminates the risk of a brick entirely (but then does require Haxchi or Browserhax to run)