I never tried a tippet ring. A blood knot, surgeon's knot, or even an Orvis knot is not impossible - even for my old fingers and eyes. At the risk of sounding like a snob, I think the knots are just more elegant.
Tippet rings as a means for making quick changes to the business end of an existing leader is fine, but IF you prefer different types of leaders for different situations like I do, it is easier to swap the entire thing and that's where a loop-to-loop connection shines.
For example, for dry flies I'll prefer either a thread furled leader or a silk woven leader with added leader material resulting in something anywhere from 5 to 15 feet+ long, generally with a lighter tippet (5X - 8X) depending on stream size, casting distance, fly size, rod length, etc.
In my world, thread furled or silk woven leaders work better than anything for dry fly fishing. I like them so much that close to 20 years ago, long before leaders that short were readily available, I had 3 foot versions made by the folks where I purchased my leaders.
However when I fish nymphs or streamers, I much prefer a 100% fluorocarbon knotted leader or a braided butt (not the same as furled) leader no longer than 6 - 7 foot long no matter where I fish because in my experience they do the job better.
So if I feel justified making the commitment to switch from fishing a size 16 beetle to a size 14 beadhead Prince Nymph...
I'm swapping leaders.
😉