What do you see as the downside of tubes?


I have decided on getting a tube amp and it will be the integrated Mastersound 300B driving a pair of Living Voice Avatars, so at least that decision has been taken.

My main question is what you see as downsides of having a tube amp. As I've decided on getting an integrated tube it's really about what the downsides are I might want to know about beforehand.

The ones I'm aware are the following.

-The tubes need to be replaced and in the case of a 300B this will be somewhat costly.

-Bias is another issue but I'm not sure how big an issue. Do you plug in your meter every so often or just when you roll tubes or replace a dead one? The meter as such isn't gonna be a big issue as I don't think it's that expensive.

-Heat won't be a big issue as we have no kids nor a nosy dog that could get burned. Hope my electricity bill isn't gonna go through the roof, but then again, I can't quite imagine that.

I'd appreciate if you could add whatever your experiences are regarding this question are as I'd like to know more before I buy it.

Thanks
krauti
I have read most of the posts and the down side has been covered very well. I have owned various high quality tube and SS amps and speaker matching is the key. I have heard your speakers with a quality 300B amp and it was magical. The only way you are really going to know about the downside of a tube amp is to buy it and decide for yourself. Yes those 300b's can be very expensive but they can also make a great heater in the winter.
my twin boys grew up with big tube amps sitting on the floor, wide open without cage. no, they never got burn.

my friend puts it best. if you can train a tiger to perform in circus, you can train your kids not to touch the tubes. 05-15-09:Semi

Obviously your boys are the exception rather than the norm. But for many of us taking the chance you took would be a bad idea.
I'd rather have a hot tube amp than a tiger. The thing with the tiger didn't go so well for Siegfried and Roy.

Well, think the thread has come to an end and I appreciate all the replies. Glad I didn't change my decision on the amp as an extra heater in the room isn't so bad. Being a mechanical engineer I might just need to design some contraption that channels the heat and put it to good use. Maybe a coated aluminum plate above the amp to fry eggs or so.
Krauti- It was a good thread;enjoy the new gear;fun wasn't it and don't forget to spray pam on the frying pan.
Rleff, thanks for the suggestion :) I might have to think about a drip can so I don't get burnt fat spots on the tubes.