I was at a recent CAPITA Partnership School event and the changes to the parents webparts do look much better, we use SLG well at our school although the use of Sharepoint is the fiddly bit. The webparts currently are not particuarly that nice to look at but the data that it needs to produce ticks the boxes.
The product will evolve, and for those schools considering SLG or moving away may decide the new features offer them something more.
I set up SLG at my last school and not only was it expensive, but we had borderline parent riots after finding out it couldn't do PDF reports at the time of launch. Staff hated it as marksheets were laggy and didn't work (even after the LA spent nearly a year with a call out on the issue), parents hated it as it was complicated and only a few really took it up. The entire thing felt like it was a half system wedged into a Sharepoint install with a 10k+ price tag slapped on top, even after PDF reports came in.
My current school was going to use SLG but decided against it after seeing the price.