Who doesn't love the feel and sound of a good v4 engine? Sure, not the BEST fuel consumption but we are talking about motorcycles here. I have ridden both RSV4's and VFR's (of several generations) and they do not disappoint aurally. The problem being the Aprilia is grossly impractical for every day riding and the VFR, current gen included, really needs another 25-35hp and proper fully adjustable suspension. The Tuono v4 is a touch less torture rack than the RSV4 but with no real wind protection and a seat that mimics a piece of broken slate it's not a true touring bike. There's also the new Motus v4, which is quite an appealing bike on paper, though a face only the designer could love (imo), and a price only the salesman would love.
Where are the good v4 touring bikes?