First, car camping with Mrs Mags is easy. We have a whole bunch of equipment and have it dialed-in. We have comfortably car camped in winter conditions, enjoy the solitude and see things that are quite awesome but not a backpacking destination (e.g. our recent trip to Chaco Canyon. Some great memories made during those outdoor experiences.
Backpacking? A learning curve for both of us. :)
I have a solo thru-hiker background and tend to be more minimalist in nature to begin with. A "blue foamer", no stove and cowboy camping is about my speed.
Mrs Mags? Even suggesting cowboy camping would skeeve her out. :) Hiking 20+ MPD with little time in camp? Er, no.
So we have to compromise. A two-person Lunar Duo. A canister stove and, AT THE MOST, 10 MPD. She wants a nice spot to relax by the lake or stream before dinner.
On her part, we don't do the 'base camp' style backpacking trips with lots of gear, little miles and mainly day hikes that she is familiar with. She has agreed to do a bit more hiking oriented trips and less of the "back country car camping" -type trips. (A nickname for the base camp style trips. :D)
So, that's my nickels worth of advice.
Find something that works for both of you. Notice I did not mention gear all the much. IMO, to successfully backpack with a spouse, it is about finding a style of backpacking that works for both of you. The gear is part of that aspect, but only a part of it.
I would not want to do basecamp trips when backpacking (climbing is another story), she does not want to do the thru-hiker style pace that I still enjoy.
So we try to find something that works both of us and is still enjoyable.