[...] For example, I love the distortion on the EAE Model feT; it is the kind of bass sound that modern bands use when try to sound old-school (think Rival Sons). But I don't think it would work on a low-passed loop, as the low end would probably get a bit too loose and unfocused (at least for what I like).
On the other hand, the Xotic Bass BB preamp would probably excel in a low passed loop (I love it full-range too), since the kind of clipping is much more focused. Also, the attack of each note gets quite compressed, which I think is really useful in this kind of crossover setup thing, since it helps to keep the low end super tight. To me, the BB preamp compresses in a way that feels really similar to the low side of the Darkglass X series. I love the feel of that compression, especially when chugging away with a pick.
The Pork Loin is another OD that has that kind of compression that I think could work on a low passed loop. It doesn't have nearly as much gain as the BB preamp (or most of the other ODs, for that matter. Is an strictly low gain pedal), and the compression is less apparent; but it's definitely there, and smoothens the note attack nicely. Additionally, it has a "curve" control that allows you to kind of select how much of the low end is going to clip (I have no idea what it actually does, but that's how it sounds to my ears

), which can be quite useful for the OP's setup.
Regarding those two pedals that the OP suggested, I have no experience with the Soul Food, but I have been using the Bass Juice forever. I'm a big fan of it, but I have inly used it full range, so I'm not sure how it'd work for the OP. It does low gain fairly good, but for me it excels at the medium gain thing (by medium gain I mean when the bass is obviously distorted in a full band mix, but not over the top). I do like the blend feature in this one. I guess it's just a normal blend, but it seems to work well with the character of the distortion. I always run it around 50-50 and (with my setup, to my ears) don't get that horrible to-completely-different-signals thing that people tend to hate on blended distortions. However, the clipping in this pedal feels more grainy and slightly fartier than in the BB preamp or Pork Loin, so I'm not sure how it would work for the OP.
Jeez, that's a lot of writing...


Bottom line: the T-Rex is stupidly cheap! Go for it and see if it works. If you can scrap together some more money, maybe the Xotic bass BB preamp is the one for you.
Whatever you get, rock the s**t out of it!



(And report back, I'm really curious about how it turns out. That Frequency Splitter is sooo high on my gas list

)