From my records (I should probably check the grafts this spring to ensure they really made it):
8/12 for splices, though that includes 3/3 on apples & pears (which I was 46/47 on anyway…) and 2 takes on mulberries, which were almost 80%. That leaves 3/6 on peaches & nectarines. But I had very different results based on early vs late for peach/nectarine (70% vs 18%). The splices break down to 60% and 0% (3/5 and 0/1), so they are on par or a bit lower. It’s worth noting I had 19/20 success with jujubes, the only failure being the one splice graft I did (18 clefts, 1 double bark all working).
I think I like splices when the scion and host are both pretty big and matching in size.
Bark Grafts:
Single: 6/10
Double: 37/64
Triple: 3/5
No matter if I did a single, double, or triple bark graft (1, 2, or 3 scions), the success rate was about 60%. 8/8 on apples and pears. For peaches/nectarines, 5/8 for early and 2/9 for late, which works out to about the same as cleft grafts.
So I think bark grafts work reasonably well for me and are a very useful for when you have a mature tree to completely work over, or have small scions (or both).
I’ll take a look to see how my splices and bark grafts look. For many, the electrical tape is still on them…
I actually prefer a bit of ugliness- nothing extreme, but a line is nice. Otherwise I’m likely to forget exactly where the graft was.
Not exactly a big sample size 
Though the same can probably be said about my “data”.
My totals: