Hi,
In my opinion it can only be personal preference. I was the same as you in that I did sports science first. I realised quite early in sports science (end of 1st year!) that physiotherapy was the way I wanted to go so i was faced with 2 options:
A - Drop out and try the BSc = 4 years (Scotland)
B - Stick it and do the accelerated route at the end = 5 years (3 remaining for sports science and 2 for MSc)
I went for B because for an extra year of my life id get a second degree as well as a masters in physio as opposed to a bachelors. You say you spoke to a physio who said theyd take a 3 year over the 2 year, each to their own I guess but in my opinion I dont see why it'd always make them a better physio. To flip the coin, I spoke to a physio before applying (fair enough it was a physio at a football club) who said the fact that I had sports science as well would make me very attractive to sports teams (as not all can afford both a physio and sports scientist - but all want both of the knowledge)... thats not to say my hearts set on working in sport though.
Also, both of the uni's I went to interviews/open days for told me that all of their masters students who had graduated this year had gone straight into jobs so I wouldnt worry too much about people thinking the accelerated course is a back door into the world of physiotherapy