Is is generally accepted here in Ireland that E. carnea, E. x darleyensis and E. erigena will suceed well in lime soils, just so long as the requirement for all heathers are met, e.g. good drainage and organic matter in the soil. They will survive quite well even on heavy clay with a little help.
The 'RHS Plant Finder' lists about 140 cultivars between the 3 species and they are used extensively here to brighten up the late winter/early spring garden.
Thanks for the info! I must say I've seen erica in more limey areas here too and they seemed fine. Calluna on the other hand, don't seem to be particularly lime-tolerant. My erica are just starting to appear from under the snow but Bell's Extra Special is already in bloom!