Those look very good !! . Nice to see you getting an early start on single barrel pens ... I believe that is the best way to introduce yourself to the basics of pen-turning. . Slimlines are harder to do. . You have made a lovely job of both.
It would be nice to know what woods you used, please. . . Also what finish you applied.
They both look very nice! The bottom one looks like to may have caught a catch or took it down just a little too much at the top tube to the center band. I'm far from being an experienced pen turner but when I started, I bought me some calipers to try to make both tubes fairly symmetrical. Now I can mostly eye it but the calipers still come in handy once in a while. I would also like to know what wood you used. They both have some nice grain to them.