Hey Gary, I've done Roadford a couple of times. Water is a bit 'fresh' but flat calm. I was wearing a surfing wetsuit rather than a tri wetsuit both times which may have protected me from the cold more. Good event. Dave Spencer and Trevor have done Roadford too so maybe ask them.
I did this last year and as Mark says the run was a real mud bath. However, I did the swim in a Tri wetsuit and the temperature was fine. Bear in mind that as a slow swimmer I tend to spend more time in the water than most! (Actually more than everyone on that occasion.)
I am planning to do it again this year, just haven't got round to booking it yet. It is a well organised event.
I have done this event in 2013 and I'm doing it again this year. I found the water cold however I was in a pretty this tri wetsuit. Bike course is undulating and the run is a tough hilly off roader around the lake. Well organised good event I thought.