depends on what type of cpu they put.. 1.5ghz sounds more like snapdragon S3 to me, imo thats more like downgrade to use qualcomn chip for LTE/3G in soc.
for example, 3G version of GNote in europe equipped with Exynos 1.4ghz, in korea they put Snapdragon S3 for LTE version, ppl found out korean version is more laggy/drain battery/higher temperature so they paid full price to get europe version.