I just got a /13 RSA23s head last night and I simply kills!! Super harmonic in both clean and diry. Ran it with two green backs and with LP w/90's, a Tele, and Gretsch Elliot Easton Duo jet all of them had great chime but still with warmth. When turned up, it has a smooth OD with just the right amount of bite. With the LP, its Zep and Billy Gibbons all the way. Seriously, some of the best tones I've heard. I also have a CJ11 which I love too which if you've read the threads, the CJ11 is very Fendery, but great in its own right. I think that I do feel some tweed in it, but it's more like a great Deluxe Reverb with more hair on it when it's clean. Perhaps due the celestion G12M all of it's tweed colors don't show through, but I prefer the G12M anyway. It's Marshally when using the mid-boost, but still grainy. I think that's where people say it's mostly tweed due to the class A style OD but with a Marshall flavor. Anyway it's great depending on what you're going for. I was surprised to find that the RSA23 did not have much more headroom than the CJ11. The RSA23 is definitely louder, but not "that" much louder. The cleans are totally different. The RSA 23 is way chimey and the CJ is very 6V6 warm cleans, very fendery. That being said, even with the cleans of the RSA being chimey, I was still able to dial a lot of warmth from it. It was able to get very warm and smokey and then also tight, cutting OD when pushed. The RSA is loud but not like the FRT37. I do not have the click channel in this head, it's the small box. But the click has always been kind of a novelty for me anyway. It rips, but I like the clean channel better. I have tried most of the D13's (including the RSA31, FRT 37, 17/39, JRT9/15, CJ11) and so far, I like this one the best. If you have a 10/20, 9/15, or CJ11 and are looking for something that has more Marshally/Voxy (maybe even Hiawatty) clean and OD, this is one to look at. The RSA23 is not a high head room amp though. With my LP, on 9 o'clock I'm starting to get some hair, with my tele about 10-11 o'clock is where clean stops. But pick attack and guitar volume will get you where you wanted to go. Do not be affaid of the volume of this amp if you already own / know the 10/20, 9/15 or CJ11 and are comfortable with the volume of those amps, The RSA23 is not that much louder. The OD is super harmonic and lively, very refined, great string definition and totallyl rockin' Tons of fun! I'm now looking at a 2x12D /13 cab to go with it.