I hemmed and hawed and eventually bit the bullet and got a virtual land line number. I think it is good to have a local number. 0800 would be next best, in my opinion.
If mobile works for you, then keep using it. But, I'm new, there are a lot of other outfits in my area, and I have to do everything possible to establish trust.
My biggest worry is that the entity who provides my number will go out of business or something and then I'll be stuck with a bunch of useless leaflets, business cards, and clients who can't find me. So, I should probably put the mobile number on there, as well.