Which Dsi flash card should i use?

What do you guys recommend? i have a r4i SDHC, which is kinda fail.. i mean now i have to buy the "new" upgraded 1.4 version that kinda sucks + there are so many r4's i don't get it, why are there copies...
Which card can keep up with the latest firmware, has solid ongoing updates.. and actually WORKS..Thankyou..

Acekard 2i (cheap with an excellent compatibility) or M3i Zero (extra functions but a little more expensive)