Tube preamp reliability vs SS?


I am considering buying a Conrad Johnson classic 2se pre or a used McCormack LD-2 preamp. 

 I have never used a tube pre, and am curious as to the reliability of the tube, I like to be able to turn it on, maybe wait 30 min for warm up before jamming tunes.  This is fine, my concern is the reliability of the tube, how long will it last?, also, is it a pain to change when it goes bad? Can I change myself, or must I send to factory just for this small tube? 

  • Would the the action of me putting in the new tube void any warranty, not that 3 years is long anyway  when it comes to warranties. 
128x128arcticdeth
Thanks to everyone.  I will stick by my SS preamps. Having a tube to change/go bad is a problem. I like the ease of just, turn on and ready to go...indefinitely.    LD-2 sent to steve for improvement is on my list. 
In some respects, it is easier to live with a tube linestage or preamp than a solid state one.  If you are someone who turns off your solid state linestage, it actually takes much longer for a solid state linestage to be fully warmed up and sounding its best; most tube gear is pretty much fully warmed up in less than 10 minutes. The big convenience factor with solid state is that you can leave a linestage on all of the time.  

In terms of ultimate longevity, in some respects, tube gear has a longer life.  It is easy to refurbish and maintain classic tube gear for decades while a lot of solid state gear is MUCH harder to find replacement transistors, ICs and op amps.

For me, the choice would come down to sonic preference and the kind of amp that the linestage/preamp will be driving.  If the amp is solid state, I would be more inclined to stick with solid state for the linestage/preamp.
I use a tube pre, despite the fact that blown tube passes DC and has smoked 2 pairs of speakers .YMMV
 Most likely a good choice for you, tubes can only increase the nervosa aspect of our hobby: hmmmm sounds a little off today, is a tube going bad, should I hunt down a NOS at ridiculous prices? You get the idea.
 Of course, if like me you were enchanted by the sound,  you're stuck.......