Should I keep around my NAD 3155?


Here is my current system:
NAD 3155 integrated
Thorens TD 145 (with Denon 110)
NAD C515BEE
Gallo Due speakers + Gallo Subwoofer

I enjoy it hugely, especially the Thorens, but I'm wondering if I'd benefit from upgrading the integrated. I'd prefer not to spend more than $1,000. Should I consider upgrading or should I just stay put?

Thanks!
dlieb
Post removed 
Thanks for the suggestions. I should've been clearer with my needs. I do have to stick with an integrated, for space reasons. Also, iPod listening is not a consideration. I listen at reasonably low levels, so power is only an issue insofar as it will boost sound quality.
I would think one of the Italian Audio Analogue integrated
amps would be a real step up.
Also, they are quite small.
Just read (Stereophile) about a new NAD integrated due out soon.
Uses the same technology as the M2 for a lot less $$$.
Could be worth waiting for!