The Pe-150, 220 GPU uses low compression pistons and will run fine on regular pump gas. It doesn't need the high octane fuel required in high compression engines. However, there are several advantages of running 100 low lead aviation fuel. You can store aviation fuel for long periods without it going stale, it has lead which helps lubricate and it has higher octane.
The big disadvantage is the lead sometimes gums up the valve guides and the valve seats and will foul a plug. If you are going to leave a tank of gas in your boat unused for several months I would rather have 100 low lead. But if you use it all the time then regular gas is fine. The best solution is to run pump gas most of the time and fill up with a tank of aviation fuel once every other month.
If you need some good scientific data on the different fuels, try the EAA website. Even the aircraft that have an STC (Supplemental Type Certificate) allowing auto gas, will benefit from occasionally filling up with a tank of 100 low lead.