I too use the 16/45 combo. Since it's a tall heavy bike I like the low first gear for taking off on hills or uneven terrain. And for me it makes third gear perfect for the type of dirt roads I spend most of my time on.
Top gear speed is not a drawback for me because I rarely cruise over 75 mph for extended periods of time. If I do then I can install the 17 tooth if I need too. But lately I've taken the lazy route and left the 16/45 as my standard gearing.