Williams was an excellent cover corner - so you can live with his sheepish tackling. The jury is very much out on Randall and his coverage skills - he's a projection for that; if he is average in coverage, and substandard as tackler and back-end defender in general - then we wasted a 1st round pick.
If he proves to be TW clone - I'd take that in a heartbeat, but I surely haven't seen anything that would indicate he has that kind speed and coverage ability.