I did a test today on both.
Cost for an electric stabilizer is around $600 plus and plus installation and running 12 volt power and adding switch. So I'm guessing around $800 total.
Cost for two manual stabilizers off eBay delivered around $50 and 4 for $80.
It's takes 4 self tapping screws each to attach them...$5.00 for whole box.
Cost for 20 volt dewalt true impact is around $200. It will actually take off lug nuts on my 2500 dodge as well as the trailer. So it has double use.
You can put a socket on it and screw the manual stabilizers to the trailer with it in minutes.
Holds a charge for easy 6 months.
Total cost with impact. $255 to $285
3 seconds for the impact....about 54 seconds for elect.
Click for video. Sorry about double pics....
Nowfor the time trail and believe me my time is very important.