This is our second boat, and our first Yamaha. First boat was $8k used and 10yrs old. We had a few small issues. This boat was $30k new. We've had a few small issues. Our dealer has been great to us the few times we've been there. Yamaha of Louisville is easy to get ahold of, communication is good during the process, and they are easy to work with when things don't go 100% as planned. I've read on a number of message boards that the dealer can make or break the ownership experience. I find this 110% true. For instance, we found a broken jet pump intake grate on our BRAND NEW (sub 10hr) boat. We brought it to the dealers attention, and nobody pointed any fingers as to whose fault it was. We don't remember hitting anything, and they don't remember looking at it before we took delivery. They attempted to get it covered under warranty, and the claim was denied under "user error" causes. HOWEVER....the dealer stepped up to keep us happy. They only charged me for the cost of the replacement part, and put it on for free during my 10hr service. Where they could have said "sorry about your luck" and docked me $125 for the part, and another 1/2-3/4hr of labor to put it on, they dropped the price so they didn't lose any money on the part, and had the service guy put it on while he was under the boat inspecting the impeller and trailer for us. Saved us some money, fixed our boat, and they looked like as much of a hero as they could while still running a profitable business. I'm completely OK with that.
As a another point of reference my neighbors bought a brand new Axis wake boat last season. Spent $75k on it. It had problems and ended up getting bought back at the end of the season. They bought a $125k Centurion to replace it. It has had a few issues as well, and the nearest dealer for them is 50 miles away. not as bad as the Axis, but what seems like par for the course for the boating market (a few trips back in the first season to fix small issues). They're leaning towards keeping this one I think.
Keep in mind that boats are not "mass produced" like cars are. SO, the QC isn't as tight, and the chance of hand assembly and human error is significantly higher. Just the nature of the beast really with a luxury product like this. Yamaha's are a VALUE leader, not really a QUALITY leader. You get what you pay for and for the most part that holds true here as well. You get a lot for your money, but you don't get everything for nothing.
So to answer the original question, brand loyalty will get you a long way. If nothing else you have experience with the brand, and a preset comfort level with the quality and value you will get for your greenbacks. For me, I'll buy another Yamaha based on my experience so far. Same for GM, Denon, Lenovo/ThinkPad, Samsung, and DeWalt to name a few. I won't buy anything else from Premier Homes, Sony, Dell, or Ford based on that same level of experience. Brand Loyalty weighs into every decision I make for major dollars ($150+), but it doesn't eclipse a good objective look at the Pros/Cons of that buying decision.