Not sure I completely agree with Vince on perfect technique and mechanics being the key. Edberg and Rafter had the worst forehands of any top player and still won slams and became number one.
Fish is in the Top 10 and his forehand is suspect though it has improved quite a bit over the years. Isner's ground game certainly leaves something to be desired.
Also important to keep in mind that Spadea has always had a super sized ego which, given his achievements on the tour, isn't entirely earned.