I compared the T394 and T454 with the XR3135 and XR4140.
The TYM was cheaper, by a decent amount, but came standard with less (e.g., only 1 rear remote, no telescoping rear links, etc.). The biggest thing I didn't like about the TYM was that the placement of the rear remote lever was in a really awkward location (on the floor). It seemed like there were just a lot of small things like that, which made it seem like the TYM just wasn't quite as well thought out.
I ended up getting the XR4145HC and haven't regretted it once. I'm at 45 trouble free and regen free hours since November 2019.