This is what you want for auto work: http://www.canadiantire.ca/en/pdp/maximum-nb-impact-wrench-0542099p.html#.Vwwf9_krJhE
Be advised they still aren't as powerful as a good air powered impact gun.
Now, to compare to your posted unit (I have assembled my cabin with one similar).
It is the best thing since sliced bread for driving screws and tightening up lag bolts etc.
This unit that is on sale at CT right now is what I have. I also have a couple of spare drills that I purchased when they were on sale. They were only $20 more than the cost of a battery alone and thus more cost effective since you get a spare drill and spare charger.
I actually have 3 drills, 1 impact gun with 4 batteries and chargers that only cost me about $300
http://www.canadiantire.ca/en/pdp/mastercraft-20v-max-lithium-ion-drill-impact-driver-combo-kit-0543188p.0543188.html?&icid=Flipp-Thu%25202016-04-07%2520to%2520Thu%25202016-04-14%2520-%2520315/115%2520+%2520weekend%2520wrap-X1A3T3#.Vwwgd_krJhE