-- Last Updated: Sep-21-12 9:13 AM EST --
To be clear - the Explorer IS the Romany but stretched. The only diff between the two is the added volume of the Explorer, developed after Nigel Dennis felt he had gotten the Romany right as a schooling boat. It was the pre-eminent schooling boat in fleets for a long time because of its combination of adaptability and head room for new paddles. We have never seen a new paddler capsize in a Romany, though it wasn't because they didn't deserve to.
I agree that the other boats you mention fit newer paddlers well, except for maybe the Capella. A coach around here has one of the first batch (before the current set of numbers and hull redesigns) that he puts new paddlers into, and while they stay upright just about every person is complaining about not being able to go straight within 20 minutes. This is on a calm river with very little wind. I've had to shepherd more than one of them home, so I hear the full litany.
Our experience is that people who are nervous in other sea kayaks get into the Romany and relax and smile, instantly. Now, that said I am talking about folks who have already gotten into some sea kayaks.
The Alchemy is in my mind a great idea because it adds a change in pace to the OPer's own stable. My only concern, and the reason I didn't mention it earlier, is that it is a highly maneuverable boat that could turn into a whirling dervish in waves. It is designed to be that kind of fun, but my husband's first sea kayak was one similar to that and there were times when he found it very discouraging to handle because of that maneuverability.
It made him a better paddler - but there were days that it was a tough introduction phase.