Depends on how you'll be using it; the full-size Prick is heavier and takes up a lot more space than the Lil Prick, so it can get to be a pain in the ass sometimes if you're not just using it at home. On the other hand the Lil Prick is so lightweight you might even forget that it's there, making it easy to use all day. It's also a lot harder to insert the plugs with the full-size model, for reasons I haven't been able to figure out, but I figure that's just because it hasn't been used much yet and still needs to be broken in.
I'd advise against using either one immediately though, the sound will be very lifeless until you let it fully warm up. And you'll need to let it warm up again even if you only turned it off for a brief moment.