It caused one graphical hang on my Mac and then it opened too many file descriptors, reaching the system limitations and I had to uninstall it and reboot.
There has been some bugs since Mavericks came out that still hasn't been fixed, mostly related to multiple monitors. That was an indication that it was going to be dropped.
It's fairly reliable but it's showing it's age right now.
I use NValt as well, but I held out for a while because I thought a new, possibly commercial, version might be on the horizon from the original developer, Zachary Schneirov. This was based on the following interview with him, which, BTW, offers some interesting background on NV.
An interview with Notational Velocity developer Zachary Schneirov
A 15km ride might be 13km of RER and 2km of biking, on some trips it's pretty damn fast even compared with a car that has to contend with traffic.
It doesn't solve the rain issue on the other hand. Especially as folding bikes generally have smaller wheels that tend to skid on wet pavement.