I am debating the 50 vs 60. I was hot to get the 60, but it looks the 50 might be a better all around unit, in that in addition to being a clip on, it can be used as a free standing thermal, also has 2x and 4x zoom, which would seem to make it a better hand held unit than the 60. I'm not sure the 60 can used as a handheld anyway. Advice?