I signed up last year (received as a Christmas present) and feel it has helped my knowledge and general approach to music. I mentioned it earlier in the thread since it was the rhythm content which drew me in.
There's not tonnes of bass guitar specific lessons, but I found I could transfer the principles to bass guitar. I have also recently started on the double bass, and it is really helpful for that! There's a lot of piano content in there for all sorts of levels.
For what it's worth I've just signed up for another year at the base level membership.