Indeed, I had pretty much the same scenario as Flashheart, I upgraded from 20mb to 50mb for only a extra few quid a month (I was still on an old ntl rolling contract), the notion of almost doubling my throughputs came second to the idea of being freed from what was then a pretty relaxed throttle program, since then it has locked down to the point of draconanism.
For a fiver a month increase I'd go for it.
For a fiver a month increase I'd go for it.