I didn't have any trouble with mine but I do prefer the M3 Perfect.
Yeah, I love my M3 Lite Perfect too. For best GBA flashcart it's a toss-up between the M3 Lite Perfect (and maybe EZ-Flash IV) and the EZ-Flash II for me.
Aside from RTC, the M3 Lite Perfect also has real-time saves, which is a great feature I don't think
any other GBA flashcart has. The in-game reset to the menu is pretty cool as well. Oh, and being able to have multiple saves!
I hate the skins though, do you have a decent one? It's also a shame that it takes quite a while to start playing: first it shows that "not endorsed by Nintendo" disclaimer, then it loads the menu, next you have to go to 'Game' and finally it has to load the game you want to play too.
EZ-Flash IV doesn't have real-time saves nor an RTC, but it loads quite a bit faster so there's that.. It still has perfect compatibility and lots of storage so it's a great option anyway.
The EZ-Flash II lacks in space (biggest version is 1 Gbit / 128 MB and was quite rare, not to mention expensive) but it does have RTC, perfect compatibility, soft reset back to the loader and it's a pure NOR-based cart so there's zero loading times whatsoever. You power on your GBA, 1-2s later it shows the loader, you select your game and it just boots. It also has a low power chip so it only uses 1.8v instead of 3.3v like retail carts.
The M3 Lite Perfect was about $90 when it was first released which was quite expensive at the time, compared to other flashcarts. It's worth a lot more these days since (all features compared), it's the best GBA flashcart that's ever been released.