B&K 125.2 Amp vs. Belles 150A (original)

Question, I currently have a B&K 125.2 amp, the original which is rated at 140w @ 8ohms. I like it a lot vs the Adcom 535 it replaced. Much more musical, and works much better with my Vandersteen 3CE Sig I speakers. Also got it for a pretty good deal, $315 shipped. 

There was another post by someone who had the same Vandersteen speakers and was looking for an amp upgrade. Belles was one of the amps recommended for the Vandersteen's (or an Arye amp, but am not looking to spend quite that much right now). 

There is a Belles 150a (original, not the 'Hot Rod' or Reference) listed on US Audio Mart, listed for $625 + shipping, or will accept offers.

My question is; is this older Belles worth it over the B&K I currently have? It seems to get/have gotten rave reviews.

As someone always looking to upgrade, would this be a good one? I can probably sell my B&K for more than I paid for it, so the upgrade  may only cost me $300 or so.

Thanks so much Johnny, your input means a lot. I may just make this person an offer, the Belles is still listed for sale.
Yes, I like the B&K as well its a good amp.The Belles will allow you to forget good and help you escape into the feeling that your on another level.Pairing with the Vandersteen's properly set up should bring a newfound level of satisfaction.   
 If I were you I would grab it asap  
  Best JohnnyR

Hi Johnny, a follow-up

I’m just received an old Belles 400A, which I purchased from Adam at High End Audio Auctions In Brooklyn, said to be working in ‘perfect’ working order. After listening most the day yesterday, it seems to be working very well. As above, I had been looking at used 150A,  and also 350A’s, but they all sold before I could make up my mind, so I jumped on this one. This amp has also received very favorable reviews from what I can find, in keeping with the other older Belles models.

Question: Unlike those other models I cannot find any specs or a copy of the original manual for the 400A on-line. I emailed David but have not heard back yet. Do you happen to have any literature on this amp? Appreciate any help you could provide.