I have an old FL8 I bought out off ebay a few years back. It does the job, last year I noticed the lights started to get dull and it was hard to see in the sunlight, so often times I was sitting face in the wind just to avoid the sunlight on it. I took it apart last weekend and cleaned the brushes per the directions on Vex website, we will see how well that works tomorrow when I get out.
If you are stuck on a Vex I would opt for the 12 or 20 since they have the flat front. The 8 and 18 have the cylinder front, which collects water and snow, which some times will obstruct your viewing area. I bought the magnifier lense, that was a waste of money, as it doesn't magnify hardly anything, and condensation always forms under it fogging up the lense.
I wouldn't be opposed to a Marcum if they work, and I don't see why it wouldn't. It is the same exact science and technology.
All the debating about the two remind of the whole Ford vs. Chevy debates, more power, more dependable, blah, blah, blah. Buy what you will confident in using and you will have success, because like I said they both use the same technology.
