Had the M750ie (21 months & 16,000 miles) - now got M1000sie.
Have done a very happy 8 months and 4500 miles on the 1000 now - and has been a very reliable bike - just like the 750.
Both clutches great, tho some did tell me that I would need to put a bigger slave cyl to make it more 'user friendly. I didnt, and have not had any probs - except very occasionally in heavy heavy traffic, when it has become a little heavy.
Obviously, I have put an open clutch cover (and stainless springs) onto this bike - and just annoy people with the lovely rattle
If I persist in travelling a warp speeds, then I really ought to fit a steering damper, food for thought as Xmas pressie hubbie - if you are reading this
All 3 bikes will come up easily at the front - I found mine did quite happily when I first got it, but soon learnt how to keep her where she should be.
I have ridden the S4 & the S4R, but as Ali says, neither 'rocked my boat', mainly cos of the looks (I feel rads should be out of sight).
The S4 is quite 'grabby', wheres the 1000 is so much more smooth. The S4R is also a bit more harsh, tho not as much as the S4.
If you read a recent review on the Monster in More Cr*p than News, they will tell you to steer clear of the M1000 as it is shakey & underpowered - what a load of 'tosh' - they obviously didnt have a proper test ride.
2nd hand 1000's are going for about £5,500 ish, if you find one. New? - about £7 - or less, depending on year of stock at dealer.
Servicing costs, well its a bit early for me to say, but I'm told the cost will be about 5 - 8% higher, than that of the 750ie I had. The S4R & S4 are about 15 - 20% more than the 1000 for the major services.
Am sure someone will be along to tell you how great the S models are tho
Charlotte