I have wide fore feet with a narrow heel and moderate to high arch. The 4ds are the only boot I've worn that didn't give me some heel slippage. I have had no blisters. I have found traction to be very good, but the soft outsoles will get torn up in time over rocky terrain. Support is very good, even with very heavy loads, but I do think really big guys will need a stiffer boot. I am about 170 lbs.
Mine held watertight for nearly a year, but now leak a little. Every boot I have had leaked eventually.
These boots are built with running shoe technology, and like running shoes, will need replacement. The midsole breaks down with heavy use, and the large number of stitches are open to wear and tear. If you can handle replacing them every couple of years, I really think they are a good option.