Online reviews seem to be mixed, some saying it doesn't work, some saying it works well..
I tried it once and it worked, I didn't use it for long time. The only problem I see with this is, if you need to remove SD card or sims or the case on regular bases, then I suppose it won't work reliably, as long as the contacts are making contact, I don't see any reason to why it won't work.
The flex cable is flimsy, it will be squeezed into the sim tray, if loaded once and not removed it should work.
Phone drops shocks or vibration may cause this to not work, depending upon how tight the case is, if that holds it nicely it shouldn't be a problem, there will be a ugly bulge on the back of the phone though.
This is a hack job, but it's nothing complicated in nature. Using this we are just tapping into sim contact points.
Depending upon the phone we might have to add padding in between with a paper in sim tray, so the contacts stay tight and solid. The adapter is just for SIM, so there is not a huge data transfer thing going on, it either will just work or not.
If you don't find a phone with dedicated SD card slot, this is the next option.