After long research, I bought xd430 few weeks ago.
I have family of 4 (wife, myself and 2 boys 3 & 6). We can all fit there and have a lot of gear - tent, sleeping bags, 3 fishing rods, fishing chest, tent mattras, cooler, etc.
3 people can fish comfortably with gear, tent, cooler. You can definitely fit the 4th person, but then would be running into issues on rivers with high streams (keep in mind, you will need 2 anchors).
If there are only 2 people, you can most likely get a quartered moose in there (capacity should also be ok).
Improvements: buy at least 8 d-rings, buy anchor/rope attachment mount, rod holders (but don't glue them to the boat - attach to benches, same goes for fish finder). Buy side strips and glue them on the bottom - this will probably extend boats life by 5-8 years. I would not put 15hp on the boat - I got 9.9 Yamaha and is more than enough power.
Almost forgot, 2 people around 75-80kg can sit on one bench.
I chose this boat for capacity and narrow width which makes it Significantly faster than sd330/430.