I don't really think it's a troll, my feeling is that the op just went light on the research but either way it's been an interesting rehash.
Nubjam,
FWIW, I have a 15 sotar and was in a very similar situation as you when I bought that boat. The big exception was the durability concern. I really wasn't worried about it, they're both (all of the usual suspects actually) durable and issues with punctures or abrasion are going to be much more dependent on the operator than the fabric. That's just my opinion.
I made my choice on design and since it's only been lightly glossed over on this thread I'll say my $.02.
I'm a huge fan of diminishing tubes. A lot more room bow and stern, lower (generally) wind profile and they typically have a more gentle transition from bow/stern to straight section. This isn't always the case, for instance the DD series seems to be rather abrupt and Maravias run a longer straight section and then turn it up a little more abruptly too. I think this transition is important when fishing as it lowers the resistance between boat and water, taking less effort to move the boat over the water (independent of flow). My choice really came down to an Aire and a Sotar SL, possibly a strike.
For me the straw that broke the camels back was that I went to buy a 6 year old aire 156d. The price was totally right and I figured I could deck it out to the 9's with all the money I was going to save. When I got there, it was sitting on a trailer, fully inflated and I was shocked at how little shape was there. It looked nothing like the wireframes, there was no continuous curve and very little bow and stern kick. I had noticed that Aires wire frames were a bit flattering, even to new boats but this boat was FLAT. In essence it had flattened out over time, probably during storage or sitting in the sun (it was also in much worse shape than I had been lead to believe) so I walked away. I really wanted a truly continuous curve (like a rockered ski, water ski or driftboat). I've since noticed that many old aire's appear flattened out. I don't know why that is but I've seen an old 143 D sitting right next to new and there is a huge difference. I've noticed it on the commercial fleets on the Gallatin as well; shiny new aires next to faded flat (profile) aires.
I settled on either a Strike or an SL following my disappointment with 156D. I just needed to decide which route. The strike is flatter, less rocker and asymmetrical, I liked the idea but was worried it was too flat and I'd just be pushing water with epiece when loaded down. So ultimately I went with the standard design SL, which I love. The only thing I'd do differently is get them to reduce the kick a little, by maybe 2" or so.
Another consideration mentioned upthread is that it is a MUCH stiffer boat than any of my friends Aires. I've messed around with it on the river and my boat will comparably stiff at 1.5 psi than my buddies aire's at 2.5 psi. At 2.5 psi the sotar is a board. You might ask why this is important to me, well I spend much less time managing air. I can inflate the boat to just less than 1 3/4 psi in 50 degree morning air and in the 80-90 degree heat of the afternoon it'll be less than 2.5; well within spec. So then I shove it in the water (it goes back to 1 3/4) and I drink a beer while my buddies are pumping. Not to mention that stiffer is easier to row and way easier to stand and fish out of.
I'm certain you'll be happy with what ever you get, but I just wanted to pass along my observations and opinions to add to the information overload. Oh and yes, with a family bigger is better. With that said, my family of 4 and two springers fit fine on the 15'er; for day trips and weeklong trips alike.