To answer the question, I have an oiless that I take to the job that
powers my trim nailers and will run my framing gun for light framing.
I have also used it for roofing with no problems. To get something
useful in a lug around compressor you will need to get something that
will kick out at least 2.5 CFM at 90 lbs. And of course, MORE is
always better depending on your needs.
Oiled compressors are generally quieter than oiless, and both of my
oiled pull an amp less than than the oiless. In this case I believe
the amp rating because my oiled compressors never blow a circuit, and
the oiless frequently do. Taking the oiled out to a job where the
breakers frequently blow seems to solve the problem.
For me, I actually prefer the oiless since there is no maintenance to
keep up with, and no oil to leak out when it has ridden around in the
back of the truck and been banged around on the job for a while.
Lots of talk about oiled compressors lasting longer than oiless, but in
actual everyday use for me that hasn't necessarily been the case. I
haven't actually had the pump itself fail on any of the last several
compressors I have owned, it is always something else that gives up,
breaks, or wears out. If it is a shop compressor, made for you to goof
around with on the weekends and evenings on projects and then maybe
some light remodeling, I would probably go with the best deal
dollarwise. Sears has some good sales on occasion on compressors that
have the same pump assembly as some of the Bostitch, Senco, and Porter
Cable compressors (made in Taiwan or Itay).
If you don't have your nail guns yet, there are some great combo deals
floating around out there.