Can't help much in terms of temperature but having recently bought a new hyperfreak, can comment on the fit. Hopefully this helps...
I struggled to get a good fit with the rip curl and sized down then couldn't get it on.
I am a MT according to the ONeill size chart but the shop guy said they size up big. I ended up with a ST and it's a perfect fit after a couple of hours in the water. I'm 183cm (6 foot) and 78kg (172lbs).
It's the comp (zipless) 5/4 and despite being past my most flexible, I found it fine to get on and off since it's so stretchy. Even got out of it fairly easily after a session when I had dead arms and could no longer paddle for a wave.
Hyperfreak did well here for fit and price too
https://youtu.be/GF6juN0tFXcPerhaps a 5/4 if you own a 3/2 but need warmth? The hyperfreak stretch could offset some of the thickness?
Overall extremely happy with my O'Neill, but only because it fits so well.