a99 vs. mklll

You know, the issue isn't whether to switch to Canon or Nikon from Sony.  The issue is that you need to switch to a more modern camera.  Even the sensor in the A77 beats the A700 for low light noise.  I know this is hard to believe, but look at the ISO performance of the various modern sensors vs. the A700 on DXO.  That said, you will get even a bigger bang for your sensitivity buck when upgrading to a full frame sensor.  I think it can be said that the price you pay for the amazing things you can do with an SLT camera, is that you loose about .5EV of light.  I think this is easily gotten around with more attention to proper exposure, and a light application of noise reduction software.  So if you have the money, I would decide more on the basis of ergonomics and functionality than brand.  Also, you already have a collection of Minolta/Sony lenses.  But check to see which of them are limited solely to APS-C size sensors.  You won't use them with a FF camera.  Play with the actual cameras at a camera store if possible.  See how the menus and buttons work.  Work with the viewfinders.  Shoot a few indoors images at the store using your own SD card.  Take it home and check the images out on your computer.  Then decide which camera suites you best, and costs what you can afford.

--
Only my opinion. It's worth what you paid for it. Your mileage may vary! ;-} www.dougwigton.com/