I lived and brewed in the USA for about four years before moving back here and the brewshop I used stocked both. Both worked fine, however, for me personally, I found the Whitelabs to be betters as I always made a starter. To simply crack the lid on the vial when it arrived by UPS and chuck it in my prepared/chilled starter mix was easy. With Wyeast, I had to wait an extra day or two whilst the pack swelled up before pitching into the starter.
Back here in Australia the place I get my stock from only has Wyeast or dried varieties, so I use both of those with success. Its just a change in the planning progress to time the weekend brew sessions.