The first two shots are not particularly enhanced by B/W conversion, but they are ok. I believe the original shots really depended on color to make them special. For The Towers shot, the formations in the background were glowing warmly in the early morning sun, and that is lost here.

The second shot has very muted colors, but they helped bring out some detail that is missing in the B/W. I posted this one in the original color a couple of weeks ago, and one of the commentors suggested I try it in B/W. So here it is, but I vote for the color version.

On the other hand, the Lion may actually be improved in B/W as the colors are ok, but don't support the photo all that much. (perhaps the color of the sky does not have much effect on the drama of a snarling lion).

A couple of the reasons I shot a lot more B/W back in the film days are:
1. B/W was cheaper to process.
2. Kodak Tri-X 400 was much faster than color, and still pretty sharp (I miss it )
3. I was more involved with arch. photography, which in those days anyway, didn't depend on color as much as other subjects.

I look forward to seeing the conversions of other folks on the site.