desert rider here . . .
Like Dudley above, dust is the main issue. But, I also get tree sap, mud, road salt, and bugs.
I power wash around once a month. I never give the Spyder any more power wash than it would get than going thorough a downpour at 60 mph - except for the wheel spokes and front struts while carefully avoiding the brakes. I never get the tip closer than 20" to any part the Spyder. The 1st minute and a half is soap. The rest of the time is rinse, with the last 30 seconds being spot free rinse. Washing, rinsing and then drying the whole bike from top to bottom.
With the humidity being usually under 15%, drying is a speed activity. I have two old soft bath towels that soak up most of the water. Then hit it with microfiber hand towels. As I am doing that I also use Armor All Ultra Shine Wash & Wax Detailer - I have used others and they are fine, but this seems to reduce static, stuff does not seem to stick to it as much, and makes both the paint and plastic parts look great - and has not left any build-up or white residue.
I also use the Armor All Detailer between washes for spot cleanups after I dust with a wax based car duster. ( the feathery/furry ones create too much static on the Spyder here and it actually becomes a dust magnet )
I save the wheels for last. Doing the front spokes and hubs are not fun, but the do clean easily if you keep up on them. The back wheel is the worse - be ready to roll the Spyder a couple of times so you can reach all of it. By the time you finish the wheels, the towels will be dirty with brake dust - don't use them on any of the paint/plastic finishes after that.
I have discovered that the mirrors will hold up to 20 gallons of water that will spill out as soon as you ride through your first turns, spraying you and the Spyder. So, unless you like to be spritzed and wiping waterspots off your showroom Spyder - AVOID GETTING WATER IN THE MIRRORS. This may be a feature and not a problem.
I think when you wash the Spyder on a regular basis, at least once every two weeks, is a good idea - it is an exceptional way to learn about the wear & tear you are going through and catch maintenance problems early on.
Tom