[T-Mobile Samsung Galaxy S II SGH-T989] kangelov:
You really aren't giving us a lot to go by. Here is my experience, if you are interested:

I use Samsung Galaxy SGH-T989D flashed with BestMod 5.0 Gingerbread with the TELUS modem (KJ3), then the T-Mobile one (UVKL1), and finally the Blaze one (UVLB7). I tried all 3 and all 3 worked, but not quite the same. I am on a local carrier in Canada called Mobilicity, a startup running on a single band (AWS 1700Mhz) with barely enough towers to cover the area it claims to serve, which is parts of the GTA (Toronto) + parts of a few other major cities. Signal isn't exactly stellar, and there are dead spots, especially downtown. This is normal, this carrier is barely 2 years old. What I was looking for is reliable data: I don't care for speed too much, honestly there isn't much speed to be had with any modem.

Enter the TELUS modem:

This one worked well overall, I used it for 4 months as it shipped with my handset (T989D is the TELUS version of the handset), and noticed that it behaves quite well. Speeds are okay, I guess, but nowhere near what people claim they are getting on more established carriers here like TELUS, Rogers and Bell. If I get 1Mbps download, I feel happy. Signal strength hovers around the 50% mark here at home, which translates to about 500kbps download and 100kbps upload during peak hour, but is okay at work: I see 3 towers from there versus only 1 from home. I haven't had complaints about indoor coverage (except for the subway and the elevators for obvious reasons). I haven't had too many dropped calls, but data is shaky when I venture a few streets away from major intersections. I was questioning if I can do better.

Enter the BLAZE modem:

I ran it for a grand total of 5-10 minutes. In these 5-10 minutes it didn't perform in any way better than the TELUS one, and it gave me no indication that it would beat any aspect of its performance. It gave me the overall impression of being a bit shaky, which is to be expected given that it is meant for a different model handset. Other users in this form reported similar experiences, and they ran it for a lot longer than mere minutes, so I didn't try very hard to get this one to work. Data was fluctuating too wildly for my taste, but when it performed well, it performed as good as the TELUS modem.

Enter the T-Mobile modem:

Now this was the modem that interested me. I've been running it for about 2 hours now, and I am about to leave it on for a little while. Overall impression is that it gives me better signal strength, which hopefully would translate into more reliable performance. Data wasn't any faster than with the TELUS modem. No speed increase, but at home I get around the 60% mark for signal strength. I am cautiously optimistic that I might finally see the coveted 4G icon in the office (quite unlikely, but I am a dreamer. Ask me on Monday.)

So there you have it: all 3 modems perform, the first and the last perform well. The middle one is shaky. Data isn't getting any faster no matter what I do, but I appear to be getting slightly improved reception with the T-Mobile modem. Something about this modem is optimized for the AWS band.

Hope this helps.