Momentus XT vs mSATA OR both?!

Hello,

The hybrid Momentus XT is 7200rpm, 750GB and has 8gb SSD built in. It "learns" your frequently used files and loads them faster.

I wasn't aware of the mSATA options when I ordered my laptop with the Momentus XT. At the moment I'm wondering which is the best way to go:

1) Stick with the Momentus XT, and maybe purchase an mSATA at later date (the vendor here has no problem installing aftermarket upgrades).

2) Go for a standard 7200rpm hdd, and invest the money paid for the momentus XT for the mSATA. the momentus XT costs about 130$.

If I choose first option, would I see any benefit from Momentus XT's 8gb SSD, or would it be an overkill? Or would the two even clash/conflict, limiting me to the (perhaps slower?) Momentus XT's performance, or other technical diffuculties, even blue screens etc?

 

Personally I would go with option 1. Go with the hybrid drive and if you feel you need it grab an msata afterwards.
Also what kind of laptop is it?
Reason behind the question is that there are laptops that their msata drives are Sata II as opposed to the faster Sata III. (the difference however is negligible if it isn't used for gaming ect)