Yes, my co-worker has already told me that my 235# body plus the instructor plus fuel will be quite taxing to a 150. I've got options for either one, but of course the 172 is quite a bit more/hour. The other option would be to take a 1/2 tank of fuel and go up for shorter flights, but I'd rather have a fuller tank I guess.
I've been thinking about going to Oshkosh for my first ever Fly-In. My co-worker is flying up there from the south western part of Wisconsin, I might tag along if he's got the room.