I could see myself enjoying a TE because of its form factor along with the mechanic keys and the lack of muscle memory required to change over.
Obviously YMMV but I actually found that the Advantage was easier to get used to than the TE. Form factor isn't an issue for me, but I like having shift, tab, slash, etc. in their usual places. Moving keys around that are less commonly used than the strictly alphabetical keys didn't work out so well for me because of how much I live in the command line. I use keys like slash, pipe, tab, and tilde a LOT so I appreciated that they were in their normal positions on the Advantage. These keys are used infrequently enough that I don't imagine much benefit from making them more (purportedly) ergonomic, but for me frequent enough that moving them around so drastically is really frustrating. A lot of people have also echoed that swapping Ctrl and swap with the TE has been very helpful, which is another example of how their funny placement can be off-putting. Plus there is also the fact that the TE isn't well-supported, which for me initially wasn't an issue, and they handled replacement of my TE that had blues very well, but now that I've used it for a while and I'm seeing more problems I can't get through to them.
TLDR having tried both and currently living with a TE, I'd recommend the Advantage over the TE more or less unanimously unless form factor is a real issue. Just wish they sold blues :/
The ergo sub-forum is probably not the best place to express this view, but I've also started to become of the opinion that ergonomic devices are only really worth it if you have or are starting to see RSI/CTS/etc. Given my disappointment with the TE and the high price of the Advantage (or even ErgoDox) I'm probably going to settle on something like a Filco Tenkeyless (or
maybe a FreeStyle, although the inclination attachments are just too expensive) until I start to feel I need an ergonomic keyboard.