I've tried a large number of flats, so a couple of questions:
1. What type of tension do you prefer? To me, TI's are an extremely well-made string, but the JF346 set really felt floppy to me, despite having one of the heaviest, if not the heaviest (well, in terms of diameter) low Bs out there (0.136).
2. Do you want some brightness in your tone, or more thump and mid-color?
The TIs won't give you much brightness at all, but they'll likely last you 4-5 years, but endurance is also a characteristic of the LaBella DTB's. I prefer the DTB's because they offer more overall tonal color to my ears and you can get several differently-gauged sets. I like the 760FS for four-string; you'll have to check them out to concoct a six-string set. TI's have the JF346 in one package.
An alternative that I have on my Ken Smith six-string FL are D'Addario Chromes. I bought the ECB81-5 set and added a CB032 high C string from juststrings for something like half of what the JF346's will run you and I love them. They are a bit bright for a couple of weeks to months, but they settle in nicely and they seem to provide more resistance than the TI's, which I need.
Here's a comparison of the TI 346s and the Chromes:
TI JF346:
B 0.136
E 0.100
A 0.070
D 0.056
G 0.043
C 0.033
Chromes:
B 0.132
E 0.100
A 0.080
D 0.065
G 0.045
C 0.032
Oddly, the Chromes feel of higher tension across the board, although the numbers suggest the biggest difference in the A and the D.