Hi John and welcome to the forum.
That's a good question. I haven't taken either through surf so, like you, I could only imagine. I agree with your thinking though -- the Revo would be much easier to take out in SoCal surf, but i12s would ride the waves in just like the old rubber rafts and just about impossible to broach. They both ride boat wakes pretty well, but the i12s is obviously more stable.
Beyond that, it gets back to priorities. The Revo is faster (more so against wind and chop) and easier to customize for fishing. The i12s is much roomier and would be fantastic for any kind of diving -- easy to re-mount and tons of room for tanks or whatever. They're both fun to sail -- again the Revo is faster but the i12s is super stable. For exercise, I like them both. I think the seating position is more comfortable in the Revo for longer trips and it feels a little more like a sports car by comparison. The i12s would carry a passenger easily. Ease of transport, storage and travel have got to be the most compelling features of the i12s, the importance of which may be pivotal to your decision.
I'm a big fan of the Turbofins and optional sailing rudder for either boat for better speed and control. I'd recommend a test ride so you can get a feel for both!
Vagabond, also welcome to the forum. Many of the dealers have a demo fleet. If you haven't already done so, check out the Hobie website or phone directory for a dealer (hopefully) close by.