I haven't owned a four cylinder bike since the 80's so I no longer feel qualified to comment on their reliability, I can say though, I've learned by helping others on their four cylinder bikes, that they need more "hard to do" maintenance, than a twin.
It just gets tight in thee, but maybe not as bad since they are all fuel injected now anyway.
They have some pretty comfortable fast bikes that will save you a lot of dough and are just as fast, in fact they use the same engine as one, I think Yamaha had one 1100 or 1300 four, they made a non crotch one with higher bars (more euro high cafe) and a more comfortable peg/seat arrangement, and the insurance is half as much the bike is just as fast and nimble, and it is much more comfortable to ride, personally I also don't care for the laid back cruiser or the chopper position on a bike, I prefer5 traditional peg placement and shorter tighter bars for my nimble street bike, my Ducati kicks ass thought traffic, but alas I am the fat turd limiting my narrowness.
http://3.bp.blogspot.com/-Byw7K0z61zU/TlKWiLVj9jI/AAAAAAAAAf8/ZsfP-70G0I4/s1600/ital+dag+2011+016.JPG vs
How much are you willing to spend on a bike, sorry if I missed if you got that specific or set a limit already.
There are lots of sweet spots depending on the bike model/brand/size.
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