I had a new rim put on in Ecuador a couple of years back (the roads there lull you in to a false sence of security then wham! ...you hit a seal change and your front tube's poking out). Turns out it was a 1.60 (Excel) which was fine for messing around over there but once back in the UK my bike had somehow turned in to a wobbly horrible, nay dangerous, beast on the road (but fine off road).
I finally sourced a new rim (entire wheel, in fact, so I still have the 1.60 for off road) and it is back to it's stable best.
Touratech are now listing a 21 X 2.15 Excel rim so they must have just started making them.
I have no experience of a 1.85 so I can't comment on what they're like; but I do wonder how the Excel 2.15 will work out.
Anyone got one yet?