So, after asking on a couple different threads about string options for the Taylor mini I decided to take one for the team... tried some alternate nylon core / metal wound strings: the Gold Tone / Labella silverbacks (.049 - .115) and the Kala Ubass silver plated (.050 - .110).
The Kala have a multi-strand core like classical guitar strings. They have a dual metal wrap (silver plated bronze I believe); the E string is tapered at the ball end for easier installation, and all strings are tapered (i.e. just the first wrap is present) at the tuners. I put them on with a bit of trepidation, tuned up, plugged in and... Ahhhh... SO much better sounding then the Taylors; much beefier tone, with a nice low mid fullness that was totally lacking before and which even EQ could not fix. Compared to the Taylors which sound like a guitar that is tuned down an octave, these sound like BASS! Still a lot of string noise, but careful playing along with rolling off some highs brings a great tone IMO.
The GT / Labella are very interesting, with a solid nylon core and a single metal wrap (also silver plated bronze afaik). There is no tapering possible, so these are more challenging to install for the E string (on both sets the A-G strings are easy to install and fit right into the split bridge pins). I had to widen the groove leading from the pin hole to the saddle slightly using a nut file, and at the tuner I used pliers to flatten the wrap so it would fit into the tuner slot. No way it would fit down the hole of the tuner. Once tuned up the E string has been holding fine for 2 weeks now (over-wrapped so the strings are locked in). For my tastes, these strings are a notch better then even the Kala's, with a nice deep sound and less finger noise though there is still some noise compared with flats or rubber Ubass strings. I LOVE playing the Taylor now, and would not hesitate to use it on an acoustic gig.
Compared with my Breedlove ABG / TI flats the Taylor has less growl and less complexity in the upper register. The longer scale and the flats also have a smoother feel, not just because they are flats but something about the response is just more refined. However, the Taylor is really fun and due to the shorter sustain works really well on certain kinds of feel, especially up-tempo stuff. To me, it's another great flavor of bass to have in the quiver.
Note that for both of the string sets, I had to install the E string in the traditional way at the bridge with the ball end tucked in front of the pin rather then through the pin slot. Not sure I see a big advantage to the split pin design, it's a bit easier to install the strings but I never had any issues with traditional bridge pins so to me the new Taylor pin design is maybe a case of a solution looking for a problem. Time will tell!
Initially I did not enlarge the nut slots, and surprisingly the Kala set played ok that way. However, some of the strings did bind so that tuning was not smooth. I was lazy and did not take care of the issue right away, brought the bass to a rehearsal and ended up breaking the A string at the tuner; I think that it built up too much tension when I tuned up since the string was sticking in the slot. I then re-sized the nut slots, installed the Labellas and haven't had any issue since.
It's been a total of three weeks now since I first mounted up the Kala's. These strings are definitely higher tension then the skinny little Daddarios, but I haven't noticed any bulge in the top at the bridge. Also did not have to adjust the truss rod. But if anybody wants to try them, just be aware that it's only been a few weeks and I'll feel much more confident after 6 months to a year. I'm willing to take the risk because I could not stand the sound of those wimpy strings.... IMO the heavier gauge strings make this into a whole different instrument.