Problem I had with the DSTwo+ is that it gets very hot after a while of use (can feel through 3ds) and it drains the battery quickly. I ended up purchasing a DSTT instead as it was a cheaper, less energy consuming, and not as hot running flashcart.
Both the DSTwo+ and DSTT have cheat support with both using the same cheat library. Both also can autopatch games so you don't need to worry about DRM.
I do prefer the DSTwo+ menu more but the DSTT has a decent menu.
As mentioned by Arecadian Fox, the DSTwo+ can play gba, gbc, snes and nes. However from my experience the only ones worth it are the gba and gb/c. the SNES was choppy and the nes cannot maintain aspect ratio.
It comes down to what you chose. I would recommend the DSTwo+ if you want a system with a good GUI and you can swap between games within DS mode without having to exit out to the main menu. If you just want to play DS games, then get a DSTT and use forwarders.