I have both a 210l starboard start and a 160ish litre 2003 Freeformula. The start was brilliant to learn on and at the time, not knowing what a proper performance board felt like, it felt great on the plane, fitted with a 54cm fin. I sold it and eventually bought it back so I could begin sailing 2-up with my 5 year old son and it is just great for that. You can't get away from the fact that it is a big, heavy board and despite the fact it pops onto the plane without any trouble, it feels just the same on the plane - big and heavy!. If you know nothing else, you'll love it. If you discover other boards, you'll retrospectively appreciate it's brilliance as a learning platform.
As for the freeformula, love it. I run 7.4 (54cm fin), 9.5 (65cm fin) or 11.0 (70cm fin) purely for recreational sailing. I've never had a true formula board for back to back comparisons of feel, pointing ability etc but at 106kg myself, it very comfortably floats me, jumps on the plane and hoots upwind, downwind and across the wind. The only alternative I can see are some of the larger freeride boards of similar volume but these are 10-15cm narrower overall and much narrower in the tail.
If you have some background to the sport and have an appreciation of how to preserve your gear when learning (avoid catapults, don't drag the sail across grippy deck) then you could get away with re-learning on something like the freeformula. Your gear would end up a little worse for wear at the end of it but you wouldn't have to change boards to progress. However, there's nothing like having a soft, padded learner board to encourage social sailing as there's nothing your mates/kids can really do to hurt it or whatever sail you rig on it. Depends if this is a direction you want to take your sailing.
Eckas.