Belles 350A Reference vs. Pass INT-150


Hello, I am currently running an Opus 21 cd player pre-out
to Belles 350A Reference to Dynaudio Special 25s. I'm wondering if the Pass INT-150 has significantly: lower noise floor and finer midrange to high frequency detail, plus better imaging than the Belles, or would this be a lateral move? Would appreciate any comments from someone who has compared INT-150 or X---.5 series with the Belles.

Also needing more inputs, so considering adding a pre-amp to the Belles instead of switching to an integrated. I liked the natural detail in the (discontinued) Herron solid state pre-amp, may consider one of the more recent Herron tube pre amps.
jmlm
The latest stereophile has a review of the INT-150, and he does compare it against the XA-30.5 and I beleive the Rogue Monoblocks - so it may be worth taking a browse through that to get an idea of its personality (at least in the reviewers system and opinion).
If you are happy with the Belles sound - matching apples to apples at least in price and upgrade, Belles has the SA-101 and is about $2.5K cheaper then the INT-150A. and about $1K cheaper then the X150.5.
However as Tvad says the final determination would be your ears and what you like.
FWIW - I would invest in a Pre-amp, if it was me :o).
Only familiar with the Belles 150A and the XA 30.5 Pass gear, but between these the move is definetly not lateral. Do you have a Pass dealer near you? This might really require an audition for you to decide - the X series is certainly a bit different sounding thatn the XA.5s
Thanks for the responses! I think that my Dynaudios would benefit from more power than the 30 watt XA 30.5, even if the sound is more liquid and refined. If I get to hear the INT-150, I'll post my impressions.
I don't think you can wrong with most anything by Nelson Pass. Good luck if you go that route!
Anyone have experience with Belles Reference 350A and Pass X-150.5, NOT XA series? XA is more expensive than both of these similarly priced competitors and considerably lower power.