These things are so personal. I'd like to think that your quote above is a false opposition - was reading today about Burtynsky's switch from 4x5 film to Phase digital on Hassy body and how much he feels it has improved his ability to make great images - but I have found that constantly changing gear so as to always 'have the best' has the downside of relentless gear testing because of today's poor QC standards. And the time spent on learning the new gear is not insignificant. This is why I'm currently ditching most everything for a pair of D800s and carefully vetted stable of glass, so I can learn it inside out and work with it in depth. But I have also often found new gear creatively challenging, and have learned a lot through getting to grips with different systems and formats.
This presupposes that one is dissatisfied with their current gear. The OP never answered that key question ... the bent of his question seems more to do with "investment" fears than whether a move to something else will advance his work ... or as Keith puts it, his "Portfolio."
The notion that new gear will challenge you is of course true ... it forces involvement, even excitement about mastering the new tool. IMO, that's a logical and mechanical endeavor and is not to be confused with inspiring you ... which I think many count on, then keep changing tools looking for the "
good, better, best" magic bullet that never comes, at least not for that reason.
Inspiration is about vision, seeing light, thinking, ideas and creativity ... and the tool either does your bidding or it doesn't ... a pure function of selecting the right tool for the applications and ideas you created, bringing us right back to "horses for courses".
Like Keith, I went from a V system to the H system and have been there ever since. The H tool is well known to me, is second nature, and basically gets out of the way for the work I do. The S2 is almost there as an invisible partner in making images ... and patience has paid off because it also can do what no 35mm DSLR can do ... meaning: do the ideas I want to do ... use light the way I want to ... complete the image I want to create.
All the best in your new venture with new tools and may they fit you and what you want to do. I'm pretty satisfied with the tools I've finally assembled. Maybe others are also?
-Marc