I've been using MPRO7 for years and it's what I've used the most. The only problem I've had with it is it taking some of the finish off of a wood SKS stock, nothing I couldn't fix. Afterall, it's meant to take moisture out.
I bought a little 1oz bottle of Lucas Extreme Duty Gun Oil, cleaned and oiled my Glock 43, and two weeks later I took it apart and none of the oil has evaporated, it was all still there. I think the Mpro7 doesn't stick around as long and things dry up after a couple of weeks, maybe except for the barrel because I put it on a little thicker.
So this is my observation: that the Lucas lasts longer than the Mpro7. It's a little more expensive though, I think it was $5 for 1oz vs $10 for 4oz for the Mpro7. They're both great, but I think the Lucas might be better.