As Keith stated, there are Volvo supporters and those who would chose to avoid them.
I have told my experiences here on TF several times. My experience with Volvo and Volvo Canada in particular started in 2005 (with a new boat) and ended when I sold that boat in late 2015.
Most brands of boat engines have made some good engines and some "not so" good engines. Volvo is not alone in that. However, from my experience with a new engine under warranty for half of the time I owned it, I found that customer service from Volvo Canada was very sub-par, bordering on bad. I found parts to be on the expensive side, and sometimes hard to get (even with a relatively new engine). Once I had to wait for a part to be shipped from the eastern US (about a week or so) and once for a part to be shipped from Sweden! With the Sweden part, I had a choice of paying for air freight (cost more than the part) or wait for "regular' shipping (long wait).
My engine suffered a lower end failure just after the 5 year mark (which theoretically meant the warranty was over), but the engine hours were below the cutoff. I had a metallugical engineer examine the failed parts, and he concluded with 100% confidence that the fault was caused by a connecting rod cap nut not being torqued properly from the factory. Independently the same conclusions were reached by the mechanic who repaired that engine and the insurance adjustor who examined it. Volvo (who did not even see the engine) decided that the cause was "user error" even though they had received a copy of the engineer's report. I had dealt with them earlier for a different issue, and again the response was "user error", with no evidence to support that. Can you say, "Standard answer"??
To be fair, Volvo did end up relenting a bit (after lots of pressure from me), and paid for my insurance deductible when my boat insurance covered most of the cost to repair that engine.
I also experienced a situation where the "local mechanic" (not in my home port) would not even look at the engine because it was a Volvo. Admittedly this would be rare.
My Nordic Tug had a Cummins 6BTA, and I loved that engine. Every mechanic knows that engine, parts are readily available and usually reasonably priced.
Volvo is a popular engine right now for new builds because they offer many incentives to the builder, that I guess other engine company's don't feel they need to offer?
"But that is just my experience, others experiences may be different."
PS - Edit: I know of 2 other boats with the same Volvo engine that suffered the same failure. Just saying.