That is my Swede 55 (Rosina) that someone posted - feel free to ask any questions about the boat.
As for single handing, the Swede is a great single handed sailboat. 95% of the pleasure sailing/cruising that I do on Rosina is single handing. For the first 8 years I did it without an autopilot, but now it has one which makes things slightly easier. I have very comfortably single handed in up to about 35 knots without concern, but I do reef a bit early if I'm alone. I rarely start the engine, but prefer to sail on and off the mooring - it is just nicer that way.
Why is it such an easy boat to sail alone? I think it is because it is extremely well behaved - it can turn quickly when you turn the helm over hard, but otherwise it stays where you want it to for enough time do what you need to do. It has very good directional stability, and low windage, so you can park the boat head to wind while you handle sails, etc. It is easy to judge how much speed you need to carry into a mooring, and it gives you plenty of time to walk up and grab the pennant before the boat starts going somewhere you don't want it to. I don't have lazy jacks or roller furling, and still have no problem. I fly the spinnaker alone in winds up to about 16-17 knots. After that you might want a second hand to get it down...
On a long course point to point race we once got 2nd place in the spinnaker division sailing against fully crewed boats, and have won the doublehanded race a couple of times - basically because the boat does what you want it to. You can take your hands off the wheel and it will keep going where you want it to. No nasty weather helm, no round-ups, etc. Just always balanced and in control.
I'm sure that others who have sailed them will agree.