Wow really. That makes the investment in one even more worth it. So I assume the Everdrive card has built in ram on it?
The memory on the TED v1 is FLASH, the memory on the TED v2 is RAM, that's what allows the TED v2 to act as a Super System Card. It also lets the TED v2 act as a memory expansion for homebrew/translations.
AFAIK the TED v2.4 is working fine in unmodified consoles, and in region-modded consoles where the region-mod is getting a high-enough voltage to actually switch quickly/cleanly.
It looks like cleaning your cartridge-slot pins to ensure a good connection may also be needed sometimes (and is a sensible thing to do occasionally, anyway).
IMHO, the TED v2.4 is the better buy at this time, but it
may require you to do a bit of Spring Cleaning on your console to get it running.
If you have a TED, you don't actually need a region-mod at all to run both region's HuCard cards on it.
So an un-modified Japanese PCE Duo + TED v2 is the cheapest way to play all the HuCard and CD/SCD games these days.
You can just leave the TED v2 permanently installed and run the hacked System Card 3 image on it to run CD games (or the System Card 1 image to run Altered Beast).