KBFI
We use Boeing Field on a fairly regular basis as a tech stop for our trips to and from Asia. There are no real negatives to be honest, good FBO, we use Modern Aviation, plenty of runway with ILS, sea level elevation and temperatures are usually moderate. Also for us Gulfstream have tech support in the area. The only downside we have come across on one or two occasions is the attitude of the customs agent. Depending as to who is on duty you may find yourself in the hands of an overly officious customs agent, but to be fair this has only happened a couple of times, for the most part the agents are courteous and friendly.