Like most people here, I've sailed both boats many times also. Owned a N6.0na for ~10 years.

Just a little diagreement with a few things said.

You CAN put a roller furler on anything, inc. a N5.8.

The N5.8 has a good bit of spare parts too, albeit not as many a the TheMightyHobie18.

The N5.8 is EASIER in the surf, (both boats have daggerboards), but the 5.8 is more responsive, and a little lighter.

You can put your family on the 5.8 and have more bouyancy available than on the TheMightyHobie18.

I didn't yet see a post here from a N5.8 owner saying, that although they own a 5.8, get the TheMightyHobie18.

Someone mentioned putting a spinaker on a TheMightyHobie18. If you're going to put a headsail on it, I'd again lean toward the N5.8, more bouyancy and forgiving hulls up front.

AND, don't any of you trap out? For how long at a time, cause that silly lip is hell on your feet, unless you're wearing a stiff soled boot. Where I sail, we don't need no boots. Much more comfortable on your feet on the N5.8

But I also understand, you already have a descent TheMightyHobie18, so as suggested, if you can swing it, buy the N5.8, sail them both a while, and after a good comparison, sell the one YOU don't like.

Happy sailing, no matter what you decide.