I've have had some past experience with Swiftco several years ago, and know the owner through a business associate. Nice guy who seems to be willing to take care of the customers. They are directly located in the Westin building in Seattle that houses the SIX (Seattle Internet Exchange). Many direct fiber connections to the exchange since they are only a few floors away from the interconnect. The only issue I saw was they do occasionally have issues with spammers getting their network blocks listed. Don't know if they've corrected that, but from a pure bandwidth connection, their data center, in Seattle at least, is going to be as good or better than anyone else in Seattle. They may have even more now, but several years ago when I was in their facility they had facilities on 3 floors of the Westin, and were expanding at a pretty good rate. I recall outages being pretty minimal, and I know for a fact they test the UPS switchovers in the building on a regular basis, to ensure they will function correctly when needed. The Westin has multiple feeds from the power grid too so its a pretty solid building power wise in general.
As far as their facilities elsewhere, I don't have any experience with those, but the Seattle facilities and service was pretty good.