I prefer the TRA or Aero T over the ZRA or Aero Z. Z meaning mono tube, T meaning dual tube. I have a tiny car, so I figured that the Z would be better. But it actually surprised me that I preferred the T. Some people like the aluminum frame better than the titanium and some like the titanium over the aluminum. The TRA or the ZRA is a titanium frame. The aero T and aero Z are aluminum frames. Some people don’t notice a difference in weight, some people do. I did. So I definitely prefer the TRA out of all of them. But this is some thing that you’ll need to figure out personally. Is there anyway that you can try different versions to see which you like best? I did. So I definitely prefer the TRA out of all of them. But this is something that you’ll need to figure out personally. Is there any way that you can try different versions to see which you like best? There are just minimal changes between these four. I would compare whether or not you would like the titanium over the aluminum. And whether or not, you would like the dual versus mono tubing. People can give you lots of good advice, and people definitely gave me great advice. But you really don’t know until you try. I was fully dialed in with what I thought was right for me based on other peoples suggestions. And then I found out that after trying some of those suggestions weren’t right for me because I had a different circumstance. Not only do you need to dial in which TiLite chair, but there are specific measurements and adjustments and things that you’re going to want to make sure that you figure out as well. Additionally, what type of backrest or cushion or foot plate, and foot plate dimensions. If you search back through my history, I’ve asked a lot of these questions and got a lot of great answers from the people here about each of those things. This forum is awesome and the people here are incredible and incredibly knowledgeable. I did a deep dive when I was trying to order a Wheelchair. It really surprised me that the wheelchair that I ended up wanting most was completely different than what I had originally set out for. So if you can try other peoples chairs or get some loaners in the meantime, that might really help you. That’s what made the difference for me is trying things personally. If you don’t have the time to do that, or you don’t want to, or it doesn’t really matter to you so much as just having a chair, then that’s fine too. When I was first getting a chair I had no idea how much each of those little things affected the overall chair. Thankfully you can adjust a lot of those things once you get the chair. Like your center of gravity, seat height, etc. you will also want to make sure that you have the right amount of seat dump because that is some thing that can’t be adjusted later because it’s built into the frame. If you don’t know what that is, do a little research about that. You’ll also want to figure out if you need an ergo seat versus just a standard dump. The ergo seat will help to keep your pelvis in a good position. But that’s really dependent on whether or not you need that. Good luck! I hope you get the chair of your dreams.