I am definitely going for an "oiled" unit. I agree, the oiless ones aren't (based on my research) going to hold up as long and tend to be noisy. The small 10 gallon one I have is sounds like it want's to take off, always has.
I was more worried about causing any problems by tipping one over on it's side for transport. I remember from working with the A/C guys in the Marines (I was an electrician [MOS:1142] back then) that if you tipped those A/C compressors on the side, you had to wait for some period of time (24 hours?) before you could power it up etc.
Anyway, thanks for the feedback