Redfin seems to have set off criticism of Microsoft’s VE API. Their reasons for their move are outlined on their blog and many seem to agree with their conclusions about Microsoft’s and Google’s mapping APIs. I’m not sure I agree the VE API is much slower than Google’s, but I suppose if you are hypersensitive you’ll notice the difference. For us it usually is local network conditions that cause one API to be slower than the other, but YYMV.
My biggest problem with Virtual Earth is trying to figure out what the heck the “Live” platform is.