View 4 is the best I've seen so far. I really like the 2 pixel border on balloons, the rounding of the corners, and the bolded text.
Also, I hope I'm not out of line here, but I'd like to share some thoughts I have on this subject, since I happen to be a bit of a cartoonist myself, and thoroughly enjoy geeking-out on the subject. You can take or leave my comments as you see fit...
I believe that the mechanics of a comic strip should not overpower the actual content of the strip. In other words, if you want readers to focus their attention on the art and dialog, you certainly wouldn't want to distract them with overly ornate or complicated borders (unless the borders are somehow relevant to the content).
I've certainly noticed my own reaction when reading newspaper comic strips, and I find that I'm somehow turned-off by comics that have outrageously thick borders or balloons. This doesn't mean that I don't like these particular comics, it just means that I don't find them as aesthetically pleasing or as easy to read. Calvin and Hobbes, for example, uses thin panel borders and balloons, and that strip is certainly easy on the eyes. I'm not a big fan of Rose is Rose, but notice how Pat Brady draws really thin panels and balloons. Your eyes are automatically directed to the artwork and dialog.
Anyway, it is my humble opinion that on stripcreator comics the text becomes overpowered by the boldness of the panel borders, and the fact that there's no gutter between the panels. This is true in all the views I've seen so far.
I think the ideal option for stripcreator is to have thinner panel borders, and to have gutters between the panels. Having gutters puts some necessary breathing room between each panel, and gives your eyes a chance to digest what you just read before going to the next panel. I think a 2 pixel border would work nicely for the borders, which would then match the thickness of the balloons. Here's a Photoshopped version of how this could possibly look:

Here's the original comic:
[Click to view comic: 'Selling Out - Part One']
My suggestions may not be possible due to limitations of the comic viewer, but I thought I'd put in my two cents. Thanks for reading this.