Good post jack-oh - PPRuNe at its best! Incidentally any comments I made weren't about your unit.
Are you perhaps being a little premature in believing SSR and TCAS make the current RAS provisions outdated? I can think of a few sources of primary-only contacts in your neck of the woods which SSR and TCAS won't help you with, and there's widespread doubt that, even if the UK officially sticks to mandatory Mode S implementation from March 2008, Paraglider Pete will (a) be in a position to shell out the money required and/or (b) give a toss about what the CAA says he should carry. So you'll still have primary-onlies - probably fewer, granted, but enough to make you think "now is that an aircraft or isn't it?" Plus there seems to be no let-up in the number of airlines who want to fly into airports with no CAS, so they'll still need the highest form of protection, which is RAS.