...in theory the same as 1-10, but divide by 2. Less accurate, but still acceptable.

5
10: perfect or nearly perfect
9: excellent, one of my all-time favorites, but 1 or 2 little things keep it from perfection

4
8: a great film, with some aspect that held me back from giving it a higher rating
7: a good, solid film, but usually not as entertaining or memorable as 8-10

3
6: a decent film, slightly above average
5: an average film, not terrible but far from great

2
4: below average, with one or two redeeming qualities in there somewhere
3: decidedly below average, with very little to redeem, getting close to bad

1
2: a poor film, nothing to redeem, but not totally bottom of the barrel
1: piss-poor, nothing I enjoyed about it and I want my lost time back

I agree it does make a diff because it's not as precise, but it can still be adapted. A 7.5 is the main rating there is no equivalent for (at least for me, and that's only an issue if you rate on a .5 scale).

my brain doesn't work correctly at this hour of the week...