I just lost my partner. It is bittersweet. I will miss his enthusiasm and ideas, but better now than after we sign a lease. And, of course, I lose his part of the investment capital. This means I will have to work for awhile to save up some capital unless I can find someone going out of pizza to take over. I have the equipment and working capital, but no longer have the construction funds.
All in all, I recommend a partner only if you cannot open any other way and you have a strong agreement in place. It does add complexity to the works.