Both these zooms receive generally good marks in online reviews. The larger lens has more range, weather seals and has not reached f/5.6 at 40mm so is a bit faster at the 14-42's long end. Adding hoods make them look similar in overall size but it's definitely not so - the 14-42 takes 46mm filters compared to 58mm on the 12-60. Weight isn't quite 2:1 but it's fairly close to that ratio. I like having 12mm but I can stitch two shots at 14mm when wide is a big deal.
So each has its values and drawbacks - no surprise there.
Here's the most valuable point of separation for me: close focus ability. Both get to nearly the same distance from an object but a 60mm closeup will out-scale a 42mm closeup every time in that circumstance. This is something I can see clearly, and that I will often use when I don't have my 10mm extension tube handy. I really don't need 1:1 closeup for my typical use (the 4Thirds 35/3.5 is for slide duplication more than general use) so flower shots and the occasional bug will do fine with the 12-60.
The last-body-ever hunt ended when a GX85 body was found for only slightly more than I expected to pay for a healthy GX7, so that's that. Complexity wins (as does updated shutter and better/dual IS!).
So here's where the kit stands now:
Body - GX85 (still holding GX1 and YI M1 w/kit lenses)
General-use lens: Lumix 12-60
Tiny telephoto: Lumix 45-150
Wide prime: Lumix 14/2.5
Bonus 4Thirds lenses: ZD 35 macro & 70-300 tele
I'd love to spend a bit on more primes some day, and maybe the 35-100/2.8. Some day will not be any time soon, barring a massive financial windfall. Not much chance of that.