Why will it not meet what we currently have?
Because there will only be one aircraft at each base, and because 3 of those bases will only be manned for 12 hours a day. It also appears very likely that SAR-H will cost rather more than the existing set-up - though exact comparison is impossible as the SAR-H process has pointedly refused to evaluate the cost of what we currently have.
No, but my earlier post was to the best of my knowledge - apologies if it turns out that I'm wrong.