Personally i like hdv, i know many people dont but to me having a hd crash and loosing all your footage just doesnt sound fun, now either does importing but id rather import then have nothing at all. Put that ontop of needing the new fcp if your going to be using an hmc150 and your costs are adding up. I personally was debating between the fx, the hmc150 or the xh a1 a few months ago. The xh won out and im very happy with the footage i have got with it.
if you want the ease of tapless but want the tapes as a backup i guess sony just came out with an addaptor for the z7u that can be used with the xh as well that integrates through the firewire port. It allows for a tape backup to be run when recording primarily to cf cards, kinda cool but im guessing that puts your right up into the price as an hmc with the new fcp studio so probably not worth it just thought id offer my two cents