Yeah, all advice is worth what it cost, so why ask a question, eh?
My experience is related to personal experience with my DUI 450CLX. It's been a great suit and when the dealer cut my seals too big, DUI stepped up and took care of it and offered to add zip seals. It has held up well at around 400 dives. I had the zippered replaced recently and it's good as new, which is good.
I do sometimes get water in my lower arms. This is when wearing wrist seals and having to manipulate a lot of stages, etc. I have the cursed wrist tendon channel. When I scooter, I really have to keep a glove cuff over the seals. When I dive with zip gloves, no worries.
The 450 is a trilam with a heavy outer layer. So, one of the first things to consider is how varied your diving conditions are. Mine are quite varied and I go up and down in insulation as I move from Lake Huron to Jackson Blue in Marianna. Also, being able to go back and forth between dry gloves and fingerless gloves is important to me. I don't travel by air too dive much as the rest of my gear isn't very 'air'able'. So, the heavy material of the 450 which also takes longer to dry, isn't an issue for me. Some like the lighter shell of a 350 TLS type of suit because of that.
As far as lucky and newer vs older on the DUI, I am on a team of divers that almost all use DUI. CLX, TLS, and Flex type. A couple have recently gotten new suits. A couple of these fellows are in the water for over 8 hours at a time while the rest of us are setting up a lot of gear and policing up after them on cave exploration dives. I am not saying the DUI is the only one out there, but all and all, they represent DS diving well.
I have to have the external boots. I spend a lot of time in rocky spring areas moving gear, etc. So the rock boot option is important to me. If I were only boat diving in the GLs, I'd probably rather not have to mess with an external boot as the tech boats are crowded and space limited, so why have another element to mess with.
I know that some are having good luck with Pinnacle suits that I think are crushed type of neo and reduce the underlayer weight. If you can afford multiple suits or dive only one condition, you might select differently. The zip seals are a point of failure, but when I go up to the Great Lakes, I don't lose a dive because of a ripped glove or neck seal. I carry a spare. And, I can go to wrist seals for most of my cave diving. So, as always, consider the 'job(s)' you are going to do and pick the tools to fit.
Feet style - back or front entry - shell material and insulation - seal types - how robustly you will use it (i.e. grind it up on rocks, etc.) - travel requirements - budget are all things I would start considering
Once I decided to go with a DUI, I got a lot of input from the guys that were mentoring me. I went with the 450 and at times I wish I would have gone with the 350, but most of the time I am glad to have the 450. I think I would have ground up a 350 by now. The 450 still looks great and it's eight years old. Many people dive much more in eight years than I do, so they may have a different experience.
