My Legend I've done the same as every other bike I've owned after doing experiments with easy to set screw and locknuts. Widest clearance within tolerance is usually a bit noisier, but gives stronger bottom end and narrows or eliminates flat spots. Tighter is supposed to give more top end but I can't say I really noticed the difference. As a result I always set clearances as wide as possible, even if they are technically in range. Especially as my Legend is running 19/40 sprockets instead of the 17/43 standard. Much relaxed cruising but it does blunt the pickup a little.
Popping the cams out isn't a chore - only done it once but I don't recall having any problem getting my wrench onto the cap bolts. Did the same trick as I learned on old Zeds - use a cable tie to lock the camchain to the sprocket and only take out one cam at a time. Just keep the bottom end on that sprocket, but easy to wedge in place with an end-on camchain.
Actually getting the seat and tank off and on is more bother than the shims. Putting the valve cover back can be a PITA especially with separate o-rings for the plug passages.
Valve shims - worth checking with your local autostore http://www.enginepartsuk.net/valvetrain.pdf
is a chart I used to cross reference and I have 4 car shims in my motor. After 3 weeks waiting for my dealer to get the ones I needed in (and still waiting) I managed to get this gem. Instead of £2.50 each exchange at the bike shop, I got 4 shims, outright for under £8 (plus a blast out on the spare bike, 55 mile round trip to collect them. But that was the same afternoon. May cross reference for Jap / Italian bike shims too if you know the sizes you need.