It's excellent. Lucy Liu is an AMAZING Watson, level-headed and smart and just the right amount of sarcastic. Jonny Lee Miller's Sherlock is brilliant too, blunt and crass,sure, though a lot more human and sympathetic than previous Sherlock incarnations.
unpopular opinion: I kinda dislike the BBC Sherlock after having watched Elementary first- the women characters aren't handled all that well and Cumberbatch's Sherlock is downright nasty to everyone. The times he is nice is nowhere near enough to redeem him. The female characters seem to be plot devices, accessories and damsels in BBC Sherlock. I don't really like the plot structure as well, it sometimes seems like things are just happening for the hell of it.
But the diversity in Elementary is superb and the mysteries presented every week are great to try and guess along the way!
There is an odd schroedinger's cat effect to my psyche though, you both want Sherlock and Joan to get nasty, but also the platonic friendship they share is amazing and you don't want that to get messed up...