If you are concerned about the mounting issues with the Xi5 (or any of the electric steer tm's), please take a look at the LiftSaver Trolling Motor Mount at www.liftsavertmmount.com.
It helps with launching your boat (sometimes the tm will hit the trailer roller and bust up the plastic covers), they have a small mounting footprint so some holes may be exposed and you typically only get 4 bolts to hold it on the bow (my plate is 20" X 8" so covers the holes, allows as many bolts as you need, you can use the existing bolt holes and you can cant the mounting to assure the control head is inside the side of your boat).
I have an 80lb Xi5 on my Z18 (18' 8") and love it. You can pm me with any specific questions or give me a call at 469-853-5389 and I will tell you more about my experience with it.
LiftSaver Trolling Motor Mounting Bracket - Patent Pendingwww.liftsavertmmount.com
Works with MG Xi5, Xi3 and MK Terrova, Ulterra, PD V2 and Riptides as well.