Firstly - I think any method of getting your old photo's into scrappable form is worth acting on!
I scan mine in from slides/ negatives or originals and I find the most time consuming issues for me are finding the photo/slide in the first place (or sorting through them) and secondly the post processing work to get them into a scrappable pic that Im happy with. Im not sure this process would save me a lot of time in that respect since Id still have to sort them and would then need to post process to my own satisfaction.
If sending them off motivates you to get those pics sorted and on disc then Id say go for it - you'll love having them to play with! (there are some great scanners out there that'll do the job for you but if you never get around to it then thats a mute point!)
If you wanna see a quickly post processed slide Ive scanned (a very poor coloured one with dirt spots all over it and not terribly clear) using my Canon check this one out for comparison
Party.