Every Tekton that I have heard after the Double Impact.
The Double Impact, for it’s price when it came out was/is a solid rock and party speaker. Fun, fast, good bass. Sure, the cabinets are borderline, and they have a fair amount of resonance. But at 3k (I think 2500 when introduced maybe?) - it was competitive.
The DISE - $2500 more, didn’t hear much if any difference from the DI. (I do see it’s down to 4k recently). Still not sure I would drop that extra 1k.
Double Impact Monitor - ah, might as well pay the 1k to get the DI.
Anything with the BE tweeters - pushing bright for me when I have heard them.
The Ulf’s and MOAB’s... honestly I just didn’t hear much more out of them then I did the Double Impact. Same sound, maybe a little more of it, same OK cabinet, paint job etc. At those price points, would be nice to have more bracing, a decent grill, and an option of veneer over the rattle can paint. (half kidding, it’s better than rattle can, but it’s not great, nor based on a friends pair - durable).
So from a disappointment standpoint - Tekton, as a line-up was disappointing to me, with one notable exception - the original DI. It’s not perfect, but no 3k speaker is. It’s a definite one to look at in that price range (but you have to get by the cabinets, so-so build quality etc). But, if I were going to do a party room/bar/big gym - heck yes they are on my list. If I were in college... I would scratch and claw to find 2k to buy a used pair.
But I would not consider any other speaker in their line-up. I also understand the caveats of customer service with Tekton. So, that is a part of it.
Others that disappointed - Focal, anytime I’ve heard them, that damn tweeter just has to be the star of the show. I did hear a pair of Sopra 2’s with a rogue tube-amp. That helped a lot, but the bass sucked then.
The Paradigm Persona ear bleed inducing line-up... too bright. (though, if your hearing has faded, or you have legit hearing damage) and you listen at low to moderate levels I could understand someone looking at these. They are at least coherant from top to bottom (something I just didn’t find with Focal). But if you like to listen remotely loud... not sure I would consider the Persona’s (maybe the big boys since the bass is powered and you could run tubes in the pre-amp, and possibly even the amp to smooth those suckers out).
Oh, Zu audio. Had a pair in the house. Love the company attitude, the speaker look, the USA build... but nope couldn’t stand them as speakers. (they were great about refunds etc)