Aguilar TLC: This pedal comes from a brand that's mainly famous for their amplifiers. "TLC" stands for Trans Linear Control, which is a new type of compression circuit they developed. Broadly generalizing, I'd say it sounds most like a VCA compressor.
The controls are well-thought-out, and each has a useful range. The threshold allows a very wide range of response, and will accommodate instruments with very low or very high output. Turning the knob clockwise lowers the threshold. The attack can be set from 10 ms to 100 ms; to be honest I don't hear much difference anywhere in there, even with extreme playing, but the attack has a good sound and feel regardless of the knob setting. The slope (ratio) control ranges from 2:1 to infinity:1, making it equally useful for light smoothing, heavier squeezing, and peak limiting. It actually does quite a good job reining in big signal peaks. Very subjectively, I prefer the tone and feel from the upper and lower ends of the slope function, compared to the middle of the range. Lower ratios have a nice "open" feel, and a high ratio with a high threshold is a very practical and good-sounding setup, while the middle settings can be a tad choked sounding. A low ratio with a "medium" threshold will give you just a bit more fullness, smoothness, and energy in your tone, without any unwanted side-effects. There is no indicator light to show when your signal has crossed the threshold, so to set that control you will need to listen carefully.
The compression action is very even and smooth at all settings, not like a squishy effect. During heavy compression the signal seems to drop below unity, which can make it sound a bit muffled, or like the highs are getting rolled off. However, I'm pretty sure what I'm hearing is just the overall signal level dropping--I was able to correct the problem 100% by either playing with less exaggerated signal spikes, or just turning up the output level of the pedal, and no highs are lost. In the same manner, heavier compression here will tighten up the low end enough that it can seem like the lowest frequencies get rolled off; but with lesser compression amounts the lows are fully present. It's doesn't have a big boomy low end though, if that's what you want. As with any compressor it will raise your noise floor the more compression (and make-up gain) you use; but it's really not bad, better than most other pedals, and at high threshold settings any noise is barely noticeable.
Tonally it is almost transparent, in a "clinical" sense. It does not add any warmth, sparkle, or other coloration that some people may want. It can fatten your tone in the way that any compressor will, by concentrating the dynamic range, but it is not comparatively fat sounding. Comparing it directly to the Markbass and Diamond pedals, those two have much more tonal magic than the Aguilar; however the Aguilar has a few advantages over them: it's smaller, and it doesn't require a special power supply. Also it has a wider range of effect and control than the Diamond, and it's a little bit better at extreme peak limiting than the Markbass (the Diamond doesn't do peak limiting). I don't presently have a Demeter or EBS to compare it with, but my memories and notes tell me that they both offer a little more tonal color than the Aguilar, and they are smaller, but they are less versatile in terms of type or amount of compression. The Aguilar has lower noise, and is a better limiter than those two as well.
The contruction is rugged and the pedal looks good. Dave at Aguilar is fairly easy to get ahold of in case of any issues. Earlier-produced units have an extended "lip" on the metal box surrounding the jacks, which can interfere with using low-profile right-angle plugs. They have fixed that situation with more recently-produced units. It runs off standard Boss-type 9VDC, and it has an unusual sliding drawer for a battery. The footswitch is not the usual 3PDT "true bypass" type, but it is a transparent and high-quality bypass. All in all, the Aguilar offers a tremendous amount of functionality in a convenient package.
Price in USD: new $199, used $150-$160