Three Men and a Dyke is brilliant... one of the very best routes on the mountain and one of the best of its genre that Ive climbed anywhere. Its named dont look back for a reason... the crux is well above good gear (you would probably get about 7-10m of air depending on your belayer and rope)... but its way up there and I reckon safe if not a wee bit electrifying. I remember gear being good (if occasionally small) for the rest of the route and was absorbed rather than worried. Still... wouldnt advise it as a first 21! The route is a fair hike to get to but very worth it. Cant remember how many bolts it had when I did it Im afraid.
The above reply re retro is obviously fishing... but please dont be tempted. There are plenty of bolts that do need to be replaced on the mountain (like the scarily small numbers on A3 sport route... which probably make it more than A3 cos I dont reckon theyd hold if you ripped at the top... sure someone will prob disagree on that too. Theres also still plenty of very dodge old bolts around).