If you are looking also at a Speedster 200:
The one criticism you will hear of the Speedster 150, is that it is on the small side! The person a purchased my boat from, loved it, but was too small for bringing his sons friends along, so he bought a bigger boat after owning the Speedster 150 for a year. As soon as I got out, I also felt it was small. I have the wife and one kid, and my parents wanted to come along. Had to take them on separate outings since it only seats 4, and did not want somebody sitting on the floor. Also feels especially small when you are next to all the bigger boats
In my case I absolutely wanted the boat to fit inside my garage (two separate single doors) which the 150 does. The Speedster 200 or Challenger would not fit because of the beam width, and I can't get them in my side yard. So I have no regrets, as I don't want a boat in my driveway all summer.
The Speedster 200 seats 7 which is more interesting for multi-familly, or lots of friends. Think carefully what size you want, if you have the room for it.
The dual 155's is a great choice: Redundancy, the power, and no SC rebuilds. The draw back is you have double the chances for problems, and double the maintenance costs (unless you do it yourself). and 250hrs is alot! Personally I would look for lower hours, and Nada says $15K average, so not a particularly good deal.