Well, you can actually singlehand a 70 footer even, (vendee globe) but I wouldn't recommend this to mere mortals.

Regulary singlehanding an I-20 seems a bit of a stretch to me, especially in any gusty or stong conditions. I remember depowering the fricking sh!t out of the rig in 20 knots conditions with 2 80-90 kg guys hanging off the side (400 lbs total).

I break my back only thinking about putting it on its road trailer, beach dolly, in its birth or on its side singlehandedly. My experience is that the less appealing these activities are, the less inclined you are to go sailing.

But really your own statement provides the answer you are looking for; you wrote :"My previous experience was years ago on a nacra 5.0 which I remember being heavy and a handful even for two"

If you think the Nacra 5.00 was too much then their is absolutely no reason to expect any improvement on these point when buying a I-20. It is both significantly heavier and requires alot more skill to depower or handle in challenging conditions, ESPECIALLY when singlehanding it. I personally feel the Nacra 5.0 is actually one of the best designs for the usage you state. I.e. : "...mostly recreational, single or with 1-2 crew, do not want a twitchy boat or one that will pitch pole."

Basically the only lesser point of the nacra 5.0 is maybe its somewhat more pronounced diving tendency, but this is one of the lesser problems of all problems you can encounter on a highly tuned up racing boat.

What is the reason you are getting rid of the Nacra 5.0 ?

Wouter