I’ve had a Challenge (Mistral or Furai, can’t remember) and a Bike-E semi recumbent. Sold them both because I never used them. It might have been not liking the attention, but I think equally it was just not getting into the groove with them. They were nice to ride but I didn’t spend the time getting used to the different ride and kept going back to my road bike.
I’ve had a quick go on an Optima Baron, which was lovely, and really fancy a ride on a Raptobike. For the moment though, with the type of riding I do (um, which is almost eff all) it’d be a waste to buy another. If my wife was keen I’d get a pair and we could do some touring, but she isn’t!