Personally, I prefer the fit and form of the Baja rack over that of the Surco. Granted, I'm sure you could purchase 2 Surcos for the same price as 1 Baja rack, but IMO, the baja rack is worth the extra money.
I'm only saying this because at one time or another, I've owned a Conferr Rack (no longer avail) a Surco Rack and a Garvin Wilderness Rack (similar to a Defender Rack). The Conferr rack mounted close to the roof, but it was noisy and not long enough for my needs. It was the perfect width though (did not hange over the sides of the vehicle). The Surco rack was too flimsy for my taste and it mounted way too high. I'll admit, it was the lightest of all the racks I've owned, but on the trail, it kept getting hung up on trees and the like. It was a bit noisy unloaded on the hwy too. The Wilderness rack has a great low profile mounting system and is very well made, but again, it was too wide (hung over the sides of the vehicle) and I kept getting it hung up on heavily wooded trails too.
While I currently have no use for a basket atop my 4Runner, just from the photos I've seen of the baja rack installed, if I ever need another basket, I would not hesitate one bit to purchase a baja rack. Granted my opinions of the baja rack are based soley on photos I've seen of it (not first hand experience), but from what I've seen, it has a very aerodynamic shape to it and appears to be very well made (Plus it does not appear to hang over the sides of the vehicle, which is a personal requirement of mine). Add to the fact that has a low profile mounting system too and it's a win-win.
2000runr, if the surco rack meets your needs, then that's all that matters. We all have different tastes. Just wanted to expression my own opinions of it.