I ordered these on a whim because of the 50% off discount code that still worked a few days ago. I received them yesterday and I also had the M5 version 2 with the MG5 driver but sold it a long time ago. From what I remember, I was very impressed with the bass but the mids and treble were pushed too far back. It wasn't my cup of tea.
When I opened the packaging, the medium dual flange tips were already on them and I managed to get a fit but I had to adjust and readjust in order to get a good fit. Flash back from when I had the MG5's. I then tried the black foam tips and it was easier to get a good fit but I still had to adjust them. I also tried sensorcom tips, shure black foam tips, and then I tried my westone um56 custom tips. Wow.
Out of all of the universal tips, I like the black foams for their comfort and sound, but the UM56 tips made and immediate difference. I can quickly and easily take them in and out of my ear (unlike my westone iems) and of course, I always get a perfect fit.
I haven't burned them in but with the UM56 tips I can literally feels the bass in my ear canals. Something the universal tips couldn't do for me. I also noticed the treble is more forward and sounds brighter but I detect no sibilance. From memory, the mg5's treble was much more subdued. The mids on the MG7 sound fuller and pushed forward a bit more, where as the MG5's mids were pushed further back and sounded more hollow. Soundstage is much better with the UM56 tips as it increases the distance from the transducer to my eardrum. Which for me, creates a very pleasant psycho-acoustic effect.
I'm going to let them burn in for a while and report back.