In no particular order, here are a few things that sometimes come as a surprise to those new to Yamaha boats....
- It takes longer for the engine to charge the house battery than it takes to drain it when you are operating off of it while floating typically (that is, if you crank the tunes at the sandbar and then return to the dock, the house battery won't be fully recharged.) So, if you spend any significant time floating on the house battery, use an external charger when you get back to shore.
- Slow speed handling is different than with outboards or stern drives. The 255XD in particular doesn't have a rudder, so there isn't any steering control when in neutral even if you have forward motion. You get used to it very quickly, but you'll want to play with it a bunch.
- In my opinion, the DriveX system isn't a panacea. I'm still getting to know it, but don't expect that it'll be like it is in the review videos. That's not so say it isn't cool, and that aspects of it will turn out to be very useful, but it isn't magic. You may or may not find that docking is more easily accomplished using throttles and steering like you would with any other boat.
- Don't be shy about going over the boat with a fine tooth comb before delivery. I personally find that Yamaha is middle of the pack when it comes to quality control / issues....but loose hardware is somewhat common and these are most easily dealt with prior to delivery. Some dealers are great about finding these things before you do, and some not so much.
- I personally really like the Yamaha mooring covers. They are pricey, but do a great job at protecting the boat. They typically need to be ordered separately and if you don't ask about it, you may be surprised not to get it at delivery. I found that it was a couple hundred dollars cheaper ordering it from another dealer than it was from the dealer I bought the boat from.
Hope this helps.