I have a long shaft 4 hp outboard on a bracket on the transom. This works very well as I can swing it up when sailing and therefore there is no drag. However weight is rather too far back but with inflatable on floor at front of saloon this doesn't cause the stern to drag.
I have a small Tohatsu 3.5 2 stroke which I use on the tender but carry in the lazarette. It fits in the outboard well and appears to push the boat well enough. I sail on the Bristol Channel so I like to have a back-up outboard in case the main one fails, which it did 2 years ago with no wind and spring tides need the Monkstone sand bank!
I don't like the idea of the well as my primary power as you have to remove the engine and replace the plug if you don't want the drag. Tghis is much more awkward than simply swinging the outboard up on the bracket.