Sure, getting an early crop with bush beans is great. Just remember, you have to bend down to pick them - don't plant more than your back can survive picking! I grow them in wide beds, planting 3 rows 18 inches apart, which grows together into a solid mass. You can get a lot of beans in a little space that way. I like "Venture" blue lake type for earliness, quality, and heavy yields.

Trying to plant earlier than you did with the pole beans this year is a bit of a gamble. Purple podded beans tend to be more cold-tolerant, you might try them for an extra-early crop. "Royalty Purple Pod" is good, but they get strings if you don't pick them real young; I like "Purple Queen", which is stringless but not as widely available (Ed Hume used to carry them, I haven't checked lately).

Perhaps after 7 years you have found some good bush beans. I have one heirloom bean, Pisarecka Zlutoluske, which is a yellow bean with red swirled seeds, that I have planted out on April 15 and it grows fast and has very early beans. I planted out peas and fava beans in February and they did well, so that is another approach to a second crop. They do take up the space a long time though.