Not sure whether if you asked Rouche you could get the Spirit pump, as both the Siprit and the D-tron pumps are missing off there product page!!!
I've been using thye spirit pump now for almost 2 years, and it does it's job not quite as easily as the others that Carbrocks has said some handy features aren't there such as the IOB, and some of the fine tuning of deliverly aren't quite as good..
With the latter, the fine tuning incredments are only going to be a real problem if you have very low insulin requirements, for most adults this isn't a problem, The Combi has improved it's increaments so this part now match the rest of the insulin pumps that are available..
You can over-come the lack of some of the wizards that other pumps feature, either by doing your own mental arthmatic (even to a certain extent work out how much IOB is stil effective) or you can actually get a software program the pocket compass that loads on a Palm OS PDA (doesn't work with windows mobile) which enables you to to recreate the missing wizards on the PDA... But is a pain in the butt at times...
The new Combi is basically an up-graded Spirit pump, with better communication built in, but still has the wizards located and combined with blood glucose meter! How much difference this make is very hard to tell, as even with pumps that all the wizards incorparated on the pump, you still have to entre a value from a Glucose meter... But with saying that you are more likely to lose or miss lay your blood glucose meter than your insulin pump!
As to the 6 year warrenty, and not having the pump replaced in this time, this is dependant on each clinic/pct I know with my clinic they replace the pump on a 4 year cycle, so you would need to ask about your clinic replacement policy..
I actually didn't get the choice (as I should have done) of pumps, it was a case of take it or leave it, I would have choosen a different one, the Animas 2020 would have been my pump of choice, but there again I am a bit of a gadget geek! I know of several pumpers who even though they have different wizards on there pumps available to them, don't actually use them prefering to calculate etc themselves... But it is all down to personal choice though..
If your clinic is giving you, your entitled choice then take a good look at the features of each pump and decided what features suit your individual needs... From delivery incredments ( if you don't need altra fine incredments, then all pumps will suit this side) to the different wizards that are available etc..