That’s a very hard call. Carmine Jewell have more color so I suspect they are slightly more healthy. Montmorency grow taller and for that reason produce more fruit. So it comes down to picking on a ladder or not? Spraying on a ladder or not? At the moment I must say there are days I don’t like to pick on a ladder but when I add up my cherries montmorency yields more in the same space but not by much. On a windy day when I need to spray I prefer carmine Jewell for sure. Montmorency is a cherry I will always grow because it is a good one. I grafted mine from my girlfriends tree and propagated another from sprouts nearby. Carmine Jewell sucker profusely so like montmorency don’t expect them to stay put. If you want them to stay put don’t put either on their own roots. That brings up another point which is montmorency on its own roots gets 20-25’ tall but there are plenty of dwarf rootstocks to put it on so technically it could stay short and not sucker. Choosing between them would be like choosing between children and at this point I don’t feel I could.