After posting this logo yesterday, several of my Twitter buddies tweeted me to say that they felt a few things were off with the spacing. Now, i'll be honest and say that I personally felt there was nothing wrong, but after thinking about it today, I decided to make the amendments they both suggested.
 
Im in two minds, but can certainly see what they were getting at. This does feel tighter and Im starting to see that the Helvetica font tends to look better with tighter kerning over loose kerning which the other version was.

I also changed the tagline description to Helvetica. 

So thanks to @christopherscot and @MillerMosaicLLC for actually coming up with some constructive crititism. Interested to see what the general thoughts are. They certainly got my mind thinking about it.

The original can be found here : New Logo Design Based on Helvetica & New York Subway