should i go with kt150's now or wait a bit??


simple question folk's,    I have two jolida 502 amps running in mono.  kt120 tube's with about 200 hours. just broken in lets say.  this is almost going on two years now so I guess Im not listening as much as I should be. I will take care of that!!    the amps are running the top end of my infinity 1b speaker panel's.   mid's and high's.  no bass work here. so the question is is it worth installing kt150's at this point in time.    for $600, I would need eight of them, what kind of improvement in sound would I get.  with just 200 hrs on 120's would you run them a little longer to at least get some use out of them.   everybody like's the 150's for the solid bass they get out of them but I would not see that running the mid/tweeter panel.   what would you guy's do if you had the $600 ready to go??  (don't answer that)   can we assume in time the 150's price will drop a little more and just wait it out .   I know it's such a tough decision here, just help me out ok. thanks
tomtab
I compared the Tung Sol 6550s (stock with the Jolida 502p) and a set of Sovtek Kt88s to the 120s and the 120s were better sounding, although the other tubes sounded pretty damn good…note the front end tubes were swapped all over the place until I wound up with a Gold Lion (12AX7)/NOS Mullard (gold pin 6201/12AT7) combo that works well…the 150s sounded much better than the 120s but the 120s were on their last legs anyway.
well,  i  installed the 150's today.  had both amps running for an hour before one amp shut down!!!.   usually when that happens its for a reason.  it happened to me once before when a 120 blew and took out the fuse with it.  so i was expecting a blown 150 for some reason.  i started the amp back up and it stayed on.  after 20 minutes i reset two of the tubes bias. was below 500mv.  all are at about 550mv. so i shut her down after about a half hour. we will see what happens tomorrow when i want to run them again.  so i will say with the one hour i have on the tubes they do sound good right out of the box. cant say they blow away the 120's right now. that will need some time for break in.  right now i would just like to see the amps stay on for more then an hour without shutting down.   since others are running 150's in their jolida's why shouldent i be able too.  dont worry, the 120's will go right back in if there seems to be a problem here. 
Quoting the immortal Harry Pearson: "If it works the first time, it's not high-end".
want to be more specific on that dweller.   you said i need more confidence. well i spent the big bucks and installed a set of the big and fancy kt150's.  one amp shut down in an hour.  so now what am i supposed to do??   hope for the best and its never going to happen again.  a friend of mine said to me a few years back when i was asking about getting a tube amp tube trouble. you know, i think he's right. had about 10 different ss amp's over the past 30 years, never any problems.  now i have problem's, go figure.   ok, so the jolida is not $10,000 bucks but it should be good enough to work without shutting down every hour.  tomorrow is another day.  the amps go on in the morning, the bias will be checked on all 8 tubes to 500mv like they want. throwing in a cd, crank it up and let see what it could do. i dare it to shut down again.  so there,   big tom here
folk's,   amps ran for 3 hours today.  all ok.   so with 4 hours on the kt 150 tubes all i can say for now is they sound good.  nothing spectacular here.  its a funny thing but when i change out gear to me there are always little improvements here and there.  not the big changes i read about in just about every post on audio sites. i think its just a little to much bs on most peoples part. yes, everything sounds different but to hear huge amounts of differences????    maybe folks want to hear a big difference because of the money spent.  to me,  it just seems to almost sound the same.  something different here and there  but no big WOW   the bass is tighter,  the mids are smother,, the high's are higher.  my amp came with 6550's  they sounded good.  put in 120's  they sounded good.  maybe a little better,hard to really hear. now 150's, they sound good also.  can i say they sound twice as good as the 120's?   no,  not right now anyway. am i expecting a big improvment down the road.  according to everybody who has 150's i am.  we'll just wait and see.   to me you want a change in sound, change out your speakers. that will do it.