As far as the tennis betting, a bet on the Player A -1.5 Sets, is exactly the same as betting that Player A goes 2-0 in Sets. I hope this makes sense. In the case of best of 5, we typically offer a -2.5 Sets line which is the equivalent of going 3-0.
I'm aware of that, however for some of my bets I wish to specify for example Cilic vs Nishikori 2-1 rather than a simple +1.5 (as you know that 1-2 also wins in the case of +1.5 sets) as they aren't the same and as such I get a different line. The -1.5 and -2.5 are great for straight sets betting, but when I want to be on matches that will go to three and I want to specify the winner of that third there is no such option.
EDIT: And is there a reason you guys don't have a wider range of betting options for the Australian Open qualifiers when some of the other bookies do? As much as I like Nitrogen, I'm being forced to go there even though I don't like their interface and the juice is horrible.