I've been trialling them myself in the last few days and they've come a long way from where they started. Different services serve different niches, the way I used to bet G&J was essential because of one feed where they were a few seconds ahead, the way I bet these days a service like SO would be more suitable because of the injury news and tracking systems.
That said, a line service is a tough sell to me at the moment. The delayed service is pretty worthless, as things move too fast and I can get the odds free from a number of sources, and I wouldn't pay $300 for the convenience the live one offers. TBH I'd probably value it at $150ish, which is pushing the current GJ price, so I may give them another go to see if their injury alerts / other features have got up to speed.