Decompression obligations in open water hit me hard, in a way that a couple of thousand feet of penetration in a cave don't.
I presume you mean psychologically, Lynne?
I guess that we are creatures of our environment, for me it's the opposite. 20-30 minutes of deco on a 30-45m dive has reached the point where it seems almost routine. You always have options, and choosing to blow your stops may not be fatal... in some respects, for the similar situation that Trace described, you can make quick decisions and deal with the outcomes immediately.
Swimming for an hour to get out of a cave, having made your choice, with your mind telling you it was the wrong one.... watching your SPG and hoping, or wallowing in grief. That time would seem awfully long to me.....
... but then I dabble in caverns, not caves, and am doing a lot more open ocean diving. That familiarity is what I think pushes us to stretch our limits... which is why I said that 30 minutes of deco is almost routine, the moment it becomes routine is the time that I need to worry about it the most.
Which is weird, as I have a certain wary-ness about caves but will be like a rat up a drainpipe when it comes to wrecks.