In most cases omnis are more "natural" sounding, for better or for worse... better if they pick up what you want to hear, worse if they pick up what you don't want to hear. Omnis are more resistant to wind issues as well.
I listen using headphones and earbuds a lot, so that DIN'ish distance between the caps sounds "normal" to me. Listening to a 20 foot split sounds whacko. Even a 3' split is too much for my taste, 2 feet is not too bad. I had some JZ's that I ran the omni caps outside last year quite a bit an NOS-like pattern 12-14 inches apart and I really liked them. It's a bit wider than DIN, but not enough to create a huge "hole in the middle". Those mics were great for that because they had a lot of sizzle and you tend to loose the high end at outdoor festivals. Omni caps aren't perfectly omni... they are somewhat directional, especially the high frequencies. That's why I tried pointing them out at 45* rather than straight ahead, and it worked well.
Last weekend I happen to ran omnis stage lip for a jazz/rock band. It's not something I normally do, but it was a good night to experiment. Todd used my CK62's and I used AT853's with omni caps (that's what I had handy). For the 1st set we ran the omnis AB about 2' apart, the second set we went healey method, 180* x 12". I preferred the healey, but probably because of the spacing. Both sets sounded incredibly clean and realistic, like you were sitting on the floor stage lip.
It's said that it's much easier to make a low cost omni that sounds decent than it is to make a card or hyper that sounds decent. Homebrew mics made with cheap Panasonic caps can sound surprisingly good. Before dropping big bucks on Neumann caps, you might seriously think about picking up some whole omni mics that might sound almost as good for much less cost. Play with setups and decide if omnis are something you like. Then you have spare mics to use on rainy days, loaners, etc.