VTL ST 150, Audio Research VT 100, mk. II

I was wondering if anyone could give some feedback on these two amps. I am thinking of replacing my Counterpoint SA 220. These are the two that are in my price range. They would be powering Vandersteen 2ce Signatures. My preamp is a Audible Illusions 3A.
Any information is appreciated.

Having owned both amps, I can tell you there are differences.
The VT 100 MK II is a solid all around performer. Nice extension, good 'staging, quiet noise floor and good dynamics. It is also a pain to bias, "needs"* expensive ARC matched output tubes and has a fan that some find objectionable to listen to. I never heard the fan during music play but it does make some sound.
The VTL is to my ears a more coherent sound. Less dry on the top and and has a touch more space and "air" in the 'stage. Bias setting is a snap and does not require matched tubes. VTL does recommend their own tubes but they are a lot less spendy than the ARC tubes. That being said, the VTL does not have XLR inputs and that is why I am selling mine. It is the latest version for sale on the 'gon used section.
The Mod 3A is a killer pre with plenty of voltage to drive either amp. The Vanersteen 2Ce Sigs are a huge value and hard to top for under $5,000.00. Either amp will drive them well. IMHO the VTL is a clearer picture into the music and recording. YMMV.

* I have heard and read a ton of discussion on the ARC tube replacement stance so please do not start a flame war (meant for the ARC die-hards, not the OP). I am just passing along what ARC has told me personally.
I think the VTL ST150 is still in production, so you could buy a new one. I think I would do that instead of taking a chance on something used and out of production. Does anyone know MSRP. I am considering going with something from VTL. I like audio res, but there are no dealers near me and i dont really like anything they make right now. I had the VT100 and loved it. I almost went for the new VS115 but thye price hike put it beyond what i want to spend right now.
I have an old style ST-150. I am driving a pair of GMA Continuum C3 HDs. This is a great combo and the amp has plenty of grunt and finesse all at once. So far it has been extremely reliable and the output tubes hold their bias. I would recommend it to anyone.

Sideways move but its nice to move when you got a jones,cheers,B
I agree with USBlues's comment. Sideways move.
Get a tech to replace the 0.68uF Wondercaps with oil caps and you will get rid of a lot of the misty dull sonic signature. Worry not this mod has nothing to do with the fragile output stage.

BTW since its an old SA220 just be very careful when turning it on and dont ever let the speaker wires short or overdrive the amp.
Thanks everyone. My usually trusty Counterpoint is in need of a repair that will equal or exceed the price I paid for it. Since my post, I have also discovered some interest in Quicksilver and Rogue along with the VTL and ARC. It depends on what comes on the market at a good price. I will continue to consider you input.
Difficult choice and depends to a large extent on the sound you are looking for. The ARC will give you a bigger, more powerful and dynamic sound overall, a bigger stage front to back and side to side. Also, better bass and more grunt. The VTL will be more gentle, will give you a fleshier mid-range, more 'tube' magic overall. Years ago I compared the VT100 to several of the VTL amps; ultimately I went with the VTL 125 MB's, but the ARC was excellent also. The VTL's just sounded better overall with my horn speakers.
I owned a the ST150 and had it paired with the AI M3B. It smoked the McIntosh MC402 it replaced big time. Far better dynamics and PRAT for about half the price. VTL will also outperform the QS amps from what I recall (having owned the Silver 60's and Silver 90's). The only reason I sold it was to pick up a pair of vintage VTL compact 100's ( el34 based).

Good luck
Glad you mentioned Quicksilver a classic combination is Audible Illusions, Quicksilver, Vandersteen. You will not find a more reliable tube amp than QS, and I'm pretty sure Richard Vandersteen owned QS V4s. I think this combination was popularized by John Rutan of Audio Connection in New Jersey - I also think he is Vandersteens largest retailer over the years. Oh, yeah, and a breeze to bias - that is important to me, and maybe you.
Thanks to all for your input. I went after a pair of Quicksilvers but didn't land them. I found a pair of Prima Luna 6 amps from Upscale Audio. They sound and look great and are easy to use and maintain. The warranty, advice and warranty also added to the deal.