What are you running now, out of curiosity?
FWIW, my take on the three having run all 3 at this point (though time is still a little limited behind the 328 and have not run it in a match yet):
I'll start at the top with the TT. TT Glass truly is on another level, including over ZCO (of course you'll never hear a ZCO owner admit this). I've quite literally run everything from Athlon Cronus to TT, and when I first got my TTs I compared side by side with 3 different ZCOs at 3 different matches and the difference is clear. I shoot in the Southeast so the ability to cut and read mirage is a huge factor for me, and the TT is on another level. This will sound crazy, but no joke, the Razor G3 is 2nd to only the TT in my book with this. The TT Turrets are great, of course, including the feel, repeatability, tracking consistency, and the tooless zero stop is GREAT. This is also the first optic I've owned that once I zero it on Friday at a 2-day PRS match, I have literally not once have had to change my zero for the rest of the weekend. Depth of field is great on the TT. FOV is one of the best on the market, being about identical to the Razor G3 and clearly wider than ZCO, but of course the 328 beats them out (Swaro finally flexing the patent...). Lastly, of every optic I've run, not one of them can be cranked to max magnification and be just as nice to be behind as say 18x like the TT can. It's actually pretty wild. My single gripe with the TT is the gen3xr reticle. The way the hash marks grow throughout each MIL is a little wonky and I really wish there was .5 mil marks on the main line. In the end, the TT deserves to be priced over all the rest.
ZCO: Really good optic and built like a tank. Eye box is nice and easy to get behind with these, and glass is very good. One thing you'll notice immediately is the FOV if you get behind a ZCO at 20x and then get behind a Razor G3 and a TT at 20x right next to it. The FOV numbers seem a little "fluffed" in the specs. I have a feeling they sacrificed a little FOV to make the eye box super nice. ZCO FOV is closer to say a Mark 5 HD. Turrets on the ZCO are great and I personally love the option of a 10 mil. ZCO reticle designs are really nice, but they are a little thicker than many others. ZCO's design of the hash mark layout is extremely well thought out and super easy to use while on the clock in say a PRS match. Depth of field on these is also very good. ZCOs track, are dependable, and hold zero. The ZCO cuts mirage better than most but just doesn't "see the mirage" like the TT does (again, the TT glass is just kinda crazy in what it can do). Ultimately, I'd say the ZCO is appropriately priced in the market and is worth it and certainly won't lose you a match.
I posted my thoughts about the 328i a couple posts above here. I'm excited to get more time behind it in order to form more solid comparisons but initial impressions are very good. My initial gut impression is that I do immediately prefer it over the ZCO right out of the gate based on the glass and the FOV. The one big question that nobody can answer yet is long term durability. For instance, the K525 had issues when left out in the sun (rumor has it they fixed that in the 525 DLR). The Razor G3s have parallax failures (I and a few friends have got bit by this one). These types of things take time to come to the surface but of course we optimistically hope nothing pops up.
You'll see Swaro discount certs popping up on the Hide PX all the time from PRS guys off prize tables. I used one to get mine. If you can grab one of those and get the 328 for under 4k, even this early on in its life I'd say it's a great buy.