I've been logging on BT for around 5 years and over this time have absolutely loved BTs logging capabilities compared to "other" sites.
One thing I'd love to see developed in the future would be the option to log the type of terrain you trained on. For example, for a run workout, below the "choose equipment" box, you'd also have a drop down menu with terrain choices. (Examples would be, Grass, Gravel, Trail, Road, Track, etc) I think this would be beneficial because as trail runner I'd love to know the percentage of running I do on the trails compared to road training.
Same for other sports. For swimming one could have the option to choose either OWS or pool swim.
And for cycling one could log maybe a track workoout, road cycling, mtn biking, etc.
Just a few thoughts I wanted to share as I think it would really bring even more athletes to BT, especially those that may veer away because they feel it's "only for triathletes".
As always, I appreciate the hard work that goes into BT. I recommend it to all my friends for logging.