For me, I wouldn't say it's too competitive. From my knowledge most of this year's applicants either started already or have deferred for next year. I pretty much got my offer straight after my interview (it took around 2-3 days?)
I don't think you need healthcare related experience (as others on the course come from completely unrelated backgrounds) but it may help with your application. If you haven't got any, I arranged 1-day experience in an imaging department (you just have find and email a hospital that does it, mine was Derby university hospital, but there are quite a few around the country!).
I think as long as you show NHS core values, a passion for learning radiography (in your interview+ personal statement) and have passed the entry requirements, you'll be good. But that's just my personal opinion!
Hope this helps!