This is a personal choice- does the set have any sentimental value? If you paint them you will lower the value of the set. But if you are going to use and love it with white chairs and are not worried about the value go for it. Another option would be to just put a fabric cover over them. You could also add two white fabric dining chairs to mix it up or store the chairs for now and get something you do like. Yet one more option, get two dining benches. Have you thought of painting the room a bright white? This could change the whole room. Then add white accents. White roses in a crystal vase. White china in the cabinet. Have fun with the room. Also, add some silver accents to bring some bling into the room.

I personally feel that it would be a shame to paint any of the pieces. However, I can see that there is probably just too much mahogany in the room. I suggest you sell the chairs as a set and replace them with chairs similar to those in photo below Then I would keep one of the storage pieces in the room and sell the other or place it elsewhere in your house.
Carolyn Albert-Kincl, ASID

I would change the light fixture to a warm champagne or silver tone. I would not paint the dining room set. Have you considered changing the fabric on the chairs. Something bright and fun. Then add some warmth to the room by painting the DR walls a soft grey. Grey is the new "in" color. Would you consider removing either the sideboard or the tall dish cabinet? They add a lot of weight to the room. I believe that's where the heaviness comes onto play.

I agree with not painting over the furniture, but try updating the room (wall color, lighting) as mentioned.

What she really needs is architecture in this room. You need some classic wainscoting because its all brown, hard lines everywhere and no contrast. I like the thought of a creamy white ivory wainscoting and grasscloth or a textured paper. I like the chairs but the mirror bubbles doesn't work with them. That is a clash. You need some real art over that sideboard buffet, a couple of candlestick lamps, accessories, and how about a carpet with some definition to it-a relief pattern or get wood and throw down a decent hand woven rug. Also that light fixture has to go. It doesn't put out enough wattage and the design doesn't work with your chairs. I'd do a drum light chandelier-something that will diffuse the light in a more attractive way. Wouldn't hurt to drop about 4-5 4" cans in this room.

If you don't like it the way it is, go for it!