It will be faster, but you will be limited by your SATA controller on your 2010 Mac. Have you upgraded to 8GB RAM?I'm planning to give my mbp 2010 a facelift and changing the internal hdd to a 120gb ssd. And for storage I'll use 2Tb harddrive connected via fw800.
Will this give me a significant speed bost compared to today?
Yes I've 8gb ram. I was thinking of using the sdd for applications mainly and the external storage for documents (music/movies) and etc.It will be faster, but you will be limited by your SATA controller on your 2010 Mac. Have you upgraded to 8GB RAM?
What will you be using the external drive for? USB2.0 is fast enough for most things. You can get a USB3.0 drive (compatible with USB2), more compatible, and it'll work with all your future USB3 computers and devices (much more useful)
Your new mba should have usb3 as mine doues, it's even faster than fw800.When I upgraded mine to SSD it made a BIG difference. Well worth it. I have a mid-09 2.53 for reference. I was also coming from the Seagate Hybrid drives which aren't exactly slow with 7200rpm and partial ssd storage.
I also use FW800 for Time Machine and am always happy to have it over USB2. Makes things much quicker. In fact the one issue I'm having preparing for my new MBA to arrive is how to handle backups now that I'm without FW.