I like SCMRs - they bring a lot to the tatting table. You can throw rings off them, which you can't do with a traditional ring, and you can close them in different ways according to what you're tatting and the look you want to achieve.
The thing that may be hardest for me is avoiding the dreaded gaposis. Here it is, fouling up my SCMR - but it can also foul up traditional rings, chains, loop-tatted rings - it's aggravating! Yes, I fixed it - as it was just three double stitches, I frogged them and (carefully) re-tatted.
The second picture shows the bead transferred to the loop of core thread. Note that the core thread has been pulled to make the loop smaller; I'm going to show you the close I use most, which is a flat close, because it locks the SCMR so it can't accidentally open.
After the shuttle thread is pulled tight to completely close the loop, the SCMR is locked closed. I have been teaching this method for over five years now, and most tatters who try it tell me they like it better than the usual method of closure, which is putting the shuttle through the SCMR loop. There is certainly nothing wrong with the usual method - to each his own, after all - but sometimes my SCMRs will re-open when I start tatting the next element of the piece, when I've closed with just the shuttle through the SCMR core thread loop.