You do not want your bettas to always be able to see each other though. Flaring is bad for them if done continually. For them to flare they have to stretch their fins and this can lead to tears. This is why at betta shows they put cards between all of the fish. The judge will pull a card or two to make to fish flare for judging purposes but they do not leave the cards out for vary long. If you make a betta flare for a little while that is ok but for extended periods is not good for them. I am in no means an expert but that man I worked with was the Grand Champion in the United States last year and I did learn a lot from him. The man who hosted the show was the president of the the largest betta organization in the U.S. I have seen these guys bettas though and I can't think of any two other people in the US (Orient might be a different story) who would know more about bettas then these two do. I know I do occassionally make my bettas flare but I did take their advice and do not do it all the time.
Signed,
Sondan
Signed,
Sondan