What do you like best?

  I'm a chain kinda guy, had an ST1300 a couple years back, shaft drive, that was cool. Have 15000 miles on this bike original chain and sprockets, can't remember the last time I had to adjust it but I don't do wheely's or burn outs with it, that stretches the hell out of them.

  I lube the chain every 400-600 miles on average with spray and wipe off the access. When it gets dirty, black with sand caked to it I'll put the bike on the stand, lay some rags down and flood it with WD-40 using the nozzle as a mini blaster while wiping it clean. Can use an entire can to do this until the rag comes up clean after wiping, I then flood it with chain lube and wipe the extra away a couple times, looks like new again.

  Most chains have rubber o-rings today, I made the mistake of using gasoline to clean one several years ago and instantly ruined it, got full of tight spots...............

  I changed the gearbox lube with the ST1300 @ about 1500 miles and it was some aweful looking stuff, replaced it with a Honda Synthetic recommended lube.

  Chains are just sexy........  

Do different climates affect the life of a belt, like out west, heat, dessert conditions, how long do they last?

Have ridden all three. Right now I'm on a Suzuki Boulevard C-90 (1599) that has a shaft. Out of all three I like the shaft for maintenance reasons but would prefer a belt for smoothness of ride. Chains are ok for power take-off and torque but require more maintenance and are a pain to keep the rear wheel clean. JMO

Never had experience with shaft's. Personally, I'll like a belt over chain. Easier to maintain and will last virtually forever.

I'm surpriseda belt can last that long, cool!

Never had a belt but had a chain on my 48 Pan and yes it is messy and a pain and in my day went through my share of sprockets but again as Rex said it depends on your riding style. Have has shafts for the last 30 and are easy to care for but really expensive to repair or replace, and the riding style is different going in and out of corners.

One of the reasons I like motorcycles is that I like to timker, hence +1 on the chain. Whenever you have a nice day or a fight w/ mother you can go clean, lube & tighten you chain.
Shaft drive makes the most sense, everything is covered, ride on the beach, down dirt roads - "so what". + in my opinion the opposed cylinder engine arrangement is the best all around way to do it w/ an air cooled engine.
Belt? Nothing wrong w/ it (NOW) but no fun, no flair.

I worked as a Maintenance Technition for 30+.. CNC Screw Machines with several using 20 or more belts driving spindles, tools and slides. Not uncommon to see taps 3/4" diameter running straight and tapered threads 1" to 2" deep and instant reverse. Cycle times if 4- 8 seconds in brass, steel, stainless steel and high strength steel for high pressure couplings. Belts running in oil, water soluble coolant and dry, 24 hours 7days for over a year without adjustments. What will take a belt out quick is something rolling between belt and sprocket like chips, nuts screws or "STONES". Check the sprocket for tooth damage if you break a belt... Stones will crush nick a tooth and break a belt. Damage to tooth will cut a new belt..flatten a tooth on the belt..damaged belt will start wearing another tooth were ever it touches... Roll the wheel around when off the ground... Should be even sound and smooth..Lumpy roll or change in tooth Buzz could be a problem waiting to dump ya. Should be treated just like a chain..There is a pitch Diameter for a sprocket is determined by number of teeth and size, pitch of the chain or belt block..When the belt is worn out, the sprockes maybe also...
I have used all three. Belts have been reliable with a pounding. Drive Shafts have run what seems forever with only a seal failure on the Moto Guzzi at 14 years old. Replaced the seal and changed the oil, good to go. No problems with the Boulevard C90 yet..

Point of interest with belts. Check with your insurance carrier. If you get a rock or road hazard in the belt, most of the insurance people I have dealt with have covered this under the comprehension minus the deductable. Just something to think about.

Have seen that mentioned before, not stone friendly.

Chain... shaft seems to bounce and push around corners.. and belt doesn't grab as fast and easier to burn up. I just recently switched from Belt to chain on my custom v-twin also

Chain all the way....you have to grease it regularly so you know its condition and when its day is up, shaft is hidden,and though its reliable, you cant see any faults, belt can say goodbye at anytime.

  chain and sprockets on my '89 sporty and belt on the dyna and belt on the softail.
Not a big fan of shafties, bad experience in the wet with a seca 750 spinning out and getting a very up close view of the front of a truck only for the tyre to grip at the last moment and miss, scared me but freaked out the young lady I had on the back so much so that the rain was not the only thing that  made everything wet! 

Back in the 70's when I was young and chains were the only thing that made the rear wheel move. I bought a new and expensive chain.Bought it home and like I did many times before boiled it in grease. That way it gets into everywhere and lasts alot longer. Well this new chain had "O' rings in it. Dump thing was I didn't read the box ! Chain was stuffed and I was out of pocket for 2 chains.Wife was real happy to boot!!!
Long live BELTS.