I'm your man....
.....Dom. I've owned a Yachtline 420 with a Suzi 40 on the tail, Yachtline 480 (75 Mercury), Medline I 480 (70 Yam) and now a Medlie II 6.00 (140 Suzi). What can I tell you ? In brief, you have no worries they are very capable boats which are comfortable, well spec'ed and very well engineered. You just need to make sure the one you're looking at has the right equipment which may or may not be of interest to you but is it's absent will cause you grief at resale.
Are you looking at one on boatsandoutboards ? Let me know what age it is and what's on the tail. Perhaps we'd be better of chatting therefore, PM me with you number and I'll give you a call.
Buy it & Use it, then sell it and buy something bigger