Depends on where you are going to dive IMHO and how cold you get.
Just some random thoughts on suits...
I dove TLS350's for a long time. They were great for travel (very light, dry quick, can be used in very cold or more temperate waters with less undies etc...). The problem for me was most of my diving was in cold water and I get cold very easily. The TLS and many combinations of undies over the years never did it for me. I was always cold. I was certainly never "warm and toasty" as so many claim to be.
So, in an attempt to help, I just bought a Pinnacle Black Ice neoprene suit in hopes that it will be warmer. I haven't tried it out yet. It is heavier for sure just carrying it around the room. It also has a neoprene neck seal and I have never used one of those before. The neoprene neck seal feels more comfy than the latex one but it is kinda strange. I guess you just fold it under towards the neck about 2-3 inches right? I assume also that I will need more weight with the neoprene suit but honestly I was wearing so many layers of thick undies with the TLS anyway that I may even out. Also, neoprene suits usually don't have the telescoping crotch like the TLS and that really helps give you some room to wiggle when taking the suit on and off. The neoprene suit fits me well and therefore is kinda hard to wiggle in and especially out of. All that said, if it keeps me warmer, then it will be worth it!
If you are planning on traveling a lot with the dry suit then I think a trilam is the way to go. If it is for cold and local diving then a neoprene should be considered. Happy hunting and good luck!
Maybe after my first dive or so in the black ice I will write up a small comparison. So far my initial thought is that I will enjoy the Black Ice except during summer months while shore diving. Maybe I will just wear shorts under it when the water is in the 60's+....I hope!
That would be sweet. Maybe the neoprene suit (a 4.5 mil compressed one in this case) will help with the "warm and toasty" thing.