Yes, fairy extensively, historically I have usually chosen late April and the first week in May in an attempt to beat the midge hatching season. Mostly on the West Coast and extensively on Skye where I once lived and worked briefly, and of course last years Far Far North Rally where we rode a fair bit of the NC500, if you want to test man and and machine try the Glen Loth road, road being a very flattering description, of course also do the Applecross Pass and then reward yourself in the Applecross Inn.
I love riding the loop above Ullapool, riding past Stac Polliagh (worth a climb to the top on a good day) onwards to Achiltibue and Polbain, then take the coast road to Lochinver and go to the world famous pie shop, then staying coastal where possible go to the fantastic ShoreHouse sea food restaurant at Tarbet, ride a dead end road to Achmelvich beach, one of nicest that you will see anywhere in the world, if you are tempted to swim, be warned, its bloody cold, especially in late April-early May, but there are some hardy buggers in this club, Phil Hogg goes in come what may, sans wet suit!.
Speaking personally I would not get to hung up on just doing the NC500, across the top is fine and down the West Coast is also, but at times it is a bit M25ish but with far nicer scenery, I would deviate off of where possible and explore, especially on the West coast, take the road to Diabeg harbour for solitude.
Let me know if you want any more info and I will get my map book out and refresh my memory a bit more, one word of warning, up top on the NC500 around Bettyhill the road road verges are broken up badly, one our members, Bill Hedley moved over to the left a bit to much to accommodate oncoming traffic, got onto the rough stuff and had to airlifted to Inverness Hospital with busted ribs etc. An easy mistake to make in a couple of seconds that can cost you dear.