Here is another option - Like most IP modifications, their value depends a lot on how you use your boat. We mostly live a board at anchor and travel to and fro by dink, and a swim platform doesn't make our life easier. We had a swim platform on the our 350, and we don't have one on our 40. On both boats we boarded/board mid-ship from the dink. We have a single step boarding ladder that hangs from the bottom of gate stantions(clips on). So to get on board it is quick step from the dink floor, to the dink seat, to the step, and then on board. The gate stantions provide a great hand holds. Also, you don't have to mess with the IP ladder at the helm. We also use our step at floating docks.
Why do it this way???? Because when the anchorage is rough the swim platform goes up and down,-- a lot. The rougher it is the worse it gets. It can easily go up and down 12". This can make getting on board from the dink hard and dangerous, especially at night. If you fall in the water it can smash your head, It also seems like it is a constant challenge to get the dink close enough to board without getting the dink caught under the platform. The gate area doesn't go up and down like this.
For calm conditions swimming, the IP ladder is just dandy. Also, if the platform doesn't fold up it makes the boat even longer for docking - not something I need.
Before you invest in a permanent boarding platform you might make a throw-away "one step boarding ladder" out of a scrap piece of 2x8 20" long. Drill two holes in each end and hang it like an old fashion swing from the two gate stantions. Use a couple of clips from Lowes and you can clip it to the loops at the base of the stantions. It should hang about half the distance between you dink seat and the deck. If you don't like it, keep the clips and throw the rest of it in the trash. If you do, make a nice one out of teak.
George
S/V Delicia