Double jump legs are great. I did break a mission with those. I was supposed to steal documents in a penthouse of a high rise. The game was expecting me to go in the ground level and up the elevator. What I did was go a block down the street and worked my way up from vendor stalls nearby buildings and climbing on their ACs and antennae worked my way to the next higher buildings until I found my self atop an antenna tower of the neighboring building. From there I could barely reach a balcony about a floor down from the roof and from there got to the top and worked my way down. The quest markers and updates broke because I stole the documents right away, but it wanted me to enter the elevator at ground level before it would accept that I stole the objective.
I've found other crazy ways around the map with them and it makes traversing the map more fun.

I'm running in a strength build so it's Hammers and shotguns all the way. Also an MG to go full ham once and a while.. I do keep a hard hitting revolver in case i have to hit something at range. Don't use it much though. Probably not the best way to min/max a character, but I'm having fun.
I tried using a Thorton Colby "Little Mule" as a nomad vehicle and don't like it much. Handling is OK and it's top speed is ok, but it's big and you need about 2km of straight road to get it up to speed. Works better offroad than in the city.