Osprey Hydraform reservoirs

I've just bought a couple of Osprey Hydraform bladders (great price at Ultimate Outdoors in case anybody's looking for one).  Should be perfect for what I want, but one thing that strikes me is that they would not be easy to repair 'in the field'.

Has anyone had any problems with theirs?  Anything to look out for and/or avoid doing?

LB - I have the 2ltr version. Overall I'm happy with it and havent encountered any problems over the last 18mts - 2yrs. My biggest frustration is not being able to detach the hose for cleaning or repair. Up to now its not been a problem (fingers crossed) but as far as I can make out if you suffered a failure on the hill, or at home for that matter, you're looking at a new bladder.

Happy to be told I'm wrong on that though.

 Edited to say I've just looked at the Ultimate Outdoors site, and seeing as they sell replacement tubes Please ignore what I wrote earlier!