Of any system I've tried, I haven't seen anything better than Ambiance. It may not be the cheapest, but it's definitely one of the most versatile, and it allows the customer to upgrade to LED at a later date without retrofitting the whole system.
For versatility, you have the option of 5W and 10W clear or frosted bulbs, 18W incandescent or xenon reflectors and up to 20W halogen MR11 plus all the LED versions all on the same track. No other system I've seen makes it so easy to get a constant light level across a countertop as this, not to mention being able to run it up into the cabinets if wanted, or along the top.
There are a lot of variables for calculating the time for rough-in, but finish on a 300W install usually takes me about 3-4 hours - that's tracks, end feeds, sockets, bulbs and transformer.