I do it last but that is because I get there for when the core workout starts, then the TRX is after. Then I am free to do whatever I like so I go to the elliptical. That all takes about 50 minutes so I go home after that! But I also walk 7 miles a day so it's enough for me.
I just got back to the gym after a long break. Mine is a Virgin Active. I used to do a lot of the Body Pump classes and other cardio stuff but got injured. So now I am trying to improve my core strength (anything has got to be better than the zero strength I have now!) to counterbalance the knee problem. So I have been doing their 15 minute core sessions (killer!) and then using the TRX for upper body. Then I do the elliptical machine (ok for my knee) for cardio.