I did a little shootout of a few Rats last week. Retiring my 80s Rat 2 in favour of something a little more pedalboard friendly - contenders were a Stomp Under foot Skinner Box, Foxpedal Wrath V2, and Tomsline Black Teeth.
first, as a baseline - I've had my Rat 2 since like 1996 and it has been a mainstay on my board since then. I pulled it this past Winter in favour of a Barber Direct Drive because I thought I wanted to get more Marshall-y and amp-like, but while it's also a great pedal, for the post-punk/shoegaze-y stuff I do the Rat topology is just better. But I have never loved the form factor of the Rat, how awkward and big it is to mount on the board, so I've been looking for an 'ultimate rat' that will give me a "better" version of the Rat sound in a smaller footprint. nb - as much as I loved my Rat 2, I only found it usable in a fairly narrow set of control settings. no matter what I tried, I always ended up back around volume @ 11:00, filter @ 1:00, and distortion @ 1:00 or thereabouts. Thick and defined distortion that's not too fuzzy and maintains that high-end scratchiness that I've learned to love.
Tomsline Black Teeth - probably the same circuit as the Mooer Black Secret, but with a third setting to go with the vintage/turbo rat settings. At first blush, sounds great. Aggressive, thick, defined. A little bright and maybe not as much clarity in the distortion as I'd like. The sweep of the distortion knob isn't great, goes from low to nearly full at around 9:00 and just gets thicker from there. Definitely better at high gain than low. the tiny black pots for volume and filter have no contrast settings markers, so I use the center detents to figure out where I am. I found myself preferring the Turbo mode if just for feeling like I've got more volume and headroom. the vintage setting, comparatively, is pretty quiet.
Stomp Under Foot Skinner Box - MXR-sized box, simple but tidy red sparkle finish and graphics, standard Rat controls. Boasts a vintage metal can LM308 and is supposedly based on the original bud box Rat from the 70s. Loads of gain and volume on tap, very effective filter sweep. Is voiced quite brightly, what bottom end is there is pretty tight. Lots of clarity in the distortion, feels really nice and fun to play.
Foxpedal Wrath V2 - a little bigger in all dimensions than the Skinner Box but top-mounted jacks so probably a wash as far as real estate goes. Very handsome-looking graphics. Also has a NOS LM308 but maybe the normal IC style rather than metal can. Adds a toggle switch for essentially vintage/turbo settings and a 'sweep' knob that controls the degree of the reutz mod applied to the tone. it's a pretty subtle control that sounds like it makes the range of the filter sweep darker? Compared to the Skinner Box, it's definitely quieter and has less gain, even in turbo mode. Also voiced darker overall, with a bigger low end, less extended high end and more complexity in the midrange.
So still undecided between the Skinner Box and the Wrath. Looks and tweakability go to the Foxpedal, but the SUF sounds more like the snarly classic Rat, although I doubt I'll ever gone above 12:00 on the gain. Also wondering if I might like having the bigger low end after I adjust my expectations of what a Rat should sound like. Will also be trying it through my other amp - a very British and darker-voiced Trace Elliot on EL84s - to see how their relative bright/dark characters translate.
----- further testing --------
so it'll be the Skinner Box. I found that I was trying to make the Wrath sound like the Skinner Box, but it just couldn't quite get the same degree of openness and string-to-string clarity. It sounded very good on its own merits and is probably more versatile, but I don't need the darker sounds it's capable of and it was always just a little more compressed and less organic sounding than the SUF.