I think the gritty mix is always going to be better for long term plantings. A lot of growers might say they don't care for the gritty mix because it dries out too quickly. Often you'll find it's a grower who hasn't even tried it, one that hasn't made it properly (particles too large), or, in some cases I'm sure it's a grower who doesn't want to make the effort, won't cop to that, so needs another excuse ..... which is fine with me. We all arrange our priorities as we see fit & there's nothing wrong with that.

If you wish and as you recognize, you can adjust the gritty mix so it's very water-retentive, just by varying the ratio of Turface:granite. If you think you'll need the extra water retention, you can try something like
4 screened Turface
3 screened conifer bark
2 crushed granite

If you need it, you could even add an extra part of Turface - just try to remember to keep the bark fraction at 1/3 of the whole or less.

Best luck!

Al

My potted citrus trees in the gritty mix (1-1-1) will start to get droopy on 95 degree days in full sun without twice a day watering. These are the large 8-10' trees not my smaller 3-4 year olds from 4winds. The top 3 inches of soil in the smaller pots will dry out on those days as well but there's enough water down below to prevent droopiness. Pretty much everything I have requires daily watering in the gritty mix during the summer (gardenias, citrus of various kinds, roses, etc).

Were I doing it again I would move to a more water retentive mix for the citrus. Depending on the size of the tree I might also replace the granite with charcoal, perlite, or a mix of them (to keep fluoride levels decent). The granite is nice in smaller pots as it helps prevent them from tipping over but when you're using 5+ gallon pots they start to get *very* heavy in a hurry.

If you have something to tie the trunk to (soft wrap that won't harm the trunk but will still keep it from tipping over) then I would skip the granite no matter the size of the tree. It's just too heavy for my taste.

Also: I wouldn't try to repot citrus during the Summer unless you're prepared to accept significant leaf drop or you have some way of protecting them from the heat/sun for quite awhile.