I've flown to both TTD and PDX in my C172. Without a doubt I got
better service and treatment at PDX. The FBO at TTD seemed like they
really couldn't give a damn. The FBO at PDX treated me very well.
Also, the rental car situation at the PDX FBO is far better than at
TTD. FWIW, to me it's no contest. I flew VFR in to both, but IFR out
of PDX and it was very easy.