Onkyo is among the hardest brands to buy lamps for, otherwise probably nice gear!!
I WAS going to say "not true" talk to dgwojo, then I noticed who wrote this.
Like others have said, look for the MKii ones, they are "upgraded" with more power.
Great units, very pretty once you fix the lamps.
Here is a TX-4500 MKii I relamped. BTW, the 4500 is much easier to relamp than the 2500.