They do indeed look close to the same. However the only things that are the same are the "power on-off' button, speaker, and screen size. The outside case is just enough different that your mount clips for the 1450 will not fit the 50. On the software side, The 50 has no "traffic", "eco-route", and cannot handle way points on your route. If you are looking for just "A to B" the 50 is a great unit. Its best advantage, that I have found is that it locks in quicker than the 1450, and because no traffic function, there are no "pop-up ads".
There are feature differences that can be charted, but the biggest difference I found was in the functioning. My 50LM seems to work faster, and be less finicky than the 13/1450 series. If I had to pick one I would get the 50, I haven't had any issues with it.
all I could find were powered mount and traffic are added. still checking on if the "special" usb cable some refer to is included with the 1450lm but here's the comparison from Garmin http://gpstracklog.com/compare/garmin-nuvi-comparison-chart
Jeff if you look a bit deeper you will find that you can put in way points. Bring up the map and poke your finger where you want the way point and you can save that spot as a new destination or a way point.