All metres are reasonable accurate (in particular, Accu-Check is sold in the EU and subject to various accuracy requirements). Thus, they may or may not be as reliable as Aviva (relative) but are certainly sufficiently reliable (absolute).
If one assumes that the claims on the packaging (fastest result, smallest sample size, least painful) are not in violation of the advertising standards code then one could, in fact, conclude that BG meters are parity products.