I haven't tried it both ways. My Oscar Schmidt Willie K tenor has the high G on the outside, where the 8-string has the low G outside. With the 5-string, it's relatively easy to pluck the single low G by itself, since it's larger than the high G. You can either snag it with the thumbnail, or just orient the pluck at an angle that only hits the low string (usually). Even though the high string is on the outside, plucking it by itself is harder and requires an upward-angled movement (or better, an upward snag with the nail) to avoid hitting the low string. I was surprised at the number of picking tunes that used the re-entrant G with normal ukes, where you can just pluck the combined strings and it sounds fine.
I would think that with it reversed, plucking the high string by itself, on the inside, would be really hard, being down lower and on the inside. It can be tricky even when it's on the outside, because of the larger low G string being so close. You would have to precisely dig the thumbnail in between the strings to get the high G by itself.
The difference may not matter all that much. In practice, I find that plucking both strings usually works fine for when you want either the high or low note. I doubt I'd change the way mine is now, with high G outside, because I don't see any advantage...it might make just picking just the low string even easier, but it's not all that hard now.
I bought mine after a recent thread on 5 strings, which I had never considered worthwhile, but I really like the configuration now; the double sets on 8 strings can be too much in a lot of cases, and this seems to give the best of both, along with the ability to use either high or low G, which I can't do on the 8 string due to the high string being on the inside.