I got a stokke for DS, who is now 2 weeks old. Currently using it with the carry cot bit. Also have the buggy board for long walks when DD is likely to get tired (she is 16kg so not likely to use it for long as the limit is 20kg).
So far I really like it. DS seems a little bumped around on uneven ground (like broken paving slabs!) and because he is still little I have put a rolled up blanket along side him in the carry cot so keep him more secure. I haven't taken it across fields yet!
Obviously baby not old enough yet to know how long it will last.
DD has been on the buggy board a couple of times and it is very easy to push on the flat, though a bit more difficult going up and down curbs etc, she likes it, I am just nervous of tipping etc. Though I have no experience of any buggy board.
Again, haven't had a pushchair with fancy suspension so not sure how it would compare, but the stokke is fine for us so far.
The other problem is the size and fitting it into the car. No problem to get it into DH's car (lexus IS200), though the chassis does not fit into the boot of my car (VW polo) unless you take off the wheels. It does fit in the footwell behind the drivers seat though. I did know all this before I bought it though and decided I wanted it anyway.
The only other hassle is the carry cot. To attach it to the chassis it needs an extra piece, which needs to be removed completely in order to separate and fold the stokke and this just adds extra time to the putting up and down! So far I have just left it up and that is working well. You don't need this piece for the seat section so it will not be as annoying when DS has outgrown the carry cot.
On the plus side, I LOVE how high up DS is, having it parked alongside tables in restaurants I think it is fab having DS high enough to see without bending down, and he can see us while we eat if he wanted. Very easy to put him in and out as well, and so light to push one handed.
The raincover is really easy to fit and has a velcro flap for quick access to the baby if needed.
Yes it is quite expensive but shopping around helps (we got ours at the baby show for a package deal including car seat etc).
HTH