Scruffydoo,
There are quite a few threads on this. Pros and Cons to both sides.For what its worth, I like the Stage one, but I am in the minority here. The Stage I amp sounds more like a 1970s master volume Marshall (think AC/DC or Velvet Revolver). Stage II has some recto tone to it. A lot of Mesa guys didnt like the Stage I because it doesn't sound like a Mesa. The stage one is the reason I switched from Marshall and Bedrock to Mesa.
The complaints about the stage one were, ice pick in your ears high end, and the fluid drive on channel two was unusable. Also, some guys wanted more gain. I cant figure out why, but thats what they wanted. Remember, the stage one received amp of the year as it was, so it cant be that bad, right?
If you get a stage one, you have to do a few things to improve the stock amp. Replace all pre amp tubes with either the GT 12AX7-M (mullard) tubes or the GT 12AX7-C (chinese). Both types of tubes are more balanced in tone, with less highs. The stock Russian pre amp tubes in the amp has high end that will rip your head off. Next, Replace the Power tubes with GT E34LS tubes in the #7 range. Not the JJ E34LS tubes. They are different tubes and sound totally different. Groove tube has the big heat sink plate on them, JJs do not. These tubes will give you tight bottom end and make the fluid drive sound the way it should have. Boogie tells you to pick Groove tubes in the 4-6 range, which is fine if you want a cold biased amp. Your not buying it new so you dont have to worry about voiding your warranty. Just so you know, I've been running my 3 boogie amps with #7s in them for over a year and a half, with no issue. The #7s bring the bias into the correct range and gets rid of the fizzy gain, and mushy bottom.
I'm sure you can get some opinions from others on the stage II. A few guys have both. Some of them like the Stage I over the Stage II, others like the II better then the stage I. If I find another Stage I in mint shape, I'll be grabbing it, if that tells you anything.
Thats my opinion, take it for what its worth........not much!
Bmarchant