The two people that I know that have the Super Cat love them. I always wondered about the blunt stern on the 'toons--if they provide too much resistance. These people haven't complained.
As an older guy, I cannot emphasize enough what a few extra pounds and bulk means. When I bought my 28lb. Renegade, several people urged me to bump up to the Rampage--only 10 more lbs. Like everyone, I have a lot more than 28 lbs to shoulder once we add the tackle, gear, oars, water, fins, etc. and I'm at my reasonable limit with weight and bulk now. With the larger 'toon I'd have to use wheels about half the time.
Spend the money if this is going to be your primary fishing craft. Honestly, although I bought my SFC from Bill about 15 years ago and still have it, I've never been a big fan. Other than ease of entry I liked my old donut better. I don't find the SFC to be all that comfortable in comparison to the Trouttraps tube or my ultralight JW Outfitters pontoon which was similar to the Super Cat in size and weight.
Super Fat Cat 12# $420
Super Cat 18# $585
Scadden Escape 22# $700
The Escape can also be used for moderate rivers, and one would imagine the Super Cat could be as well.