With the current banner on Standard Summon (Friend Point summons), I predict that many F2P players who have been hoarding their FP's for this banner will finally get to have the experience of summoning units by the 10's for the first time in a long time. This presents a great opportunity to figure out what the rates of Great Success and Amazing Success enhancements are! My preliminary results are as follows:

Success: 88 (94.6%) Great Success: 5 (5.4%) Amazing Success: 0*

While I did not get any amazing successes after I started tracking my enhancements, I did see one just before, and I have seen them in the past, so they aren't super super rare. With that in mind, my estimate on success rates are as follows:

Success: 94% Great Success (1.5x exp): 5% Amazing Success (2x exp): 1%

I know it's a fairly small sample size, so if anyone cares to tally their enhancements and submit the data, I'll compile that into a better estimate.