Thanks for your replies, folks. I must admit I was more concerned about taking up too much RT airtime especially around the busy South of the UK but it looks like it's the norm to offer the heading as well. Wilco.
In answer to your questions:
Phantom99, my airline teaches us to round up/down to the nearest 5 degrees. I remember the reason being that you guys only ever ask us to fly 0 or 5 degrees headings and nothing in between.
Ta!
MB