I have one of each. The Marlin will shoot fairly consistent dime sized 5 shot groups with Remington Golden Bullet bulk pack from Walmart at 50 yards. The CZ will only do that with a premium ammunition although I have had good luck with Federal AutoMatch which is only a little more expensive than the Remington. My .22's are for plinking so the one that shoots the smallest groups with the cheapest ammo is the one I like best because I can afford to shoot it more.
My CZ is a trainer w/Brook's trigger kit and basically everything else he sells for the CZ's. It has a 3x9 scope on it now and that scope was on the Marlin. I took it off to put a set of XS Ghost rings on the Marlin.
The 39a I bought used 4 years ago and didn't do anything to it. It was made in 86 and didn't look like it had seen much use before I bought it.
If I had to sell one the CZ would go and the Marlin would stay, but neither are going anywhere. They are both great guns. Actually I was looking for a used 39a since I just couldn't bring myself to spend the price of a new one. After looking for close to a year for one at a reasonable price I stumbled on the CZ's and Gander Mountain was having a sale so the Trainer came home. Shortly after that I moved to a new city and within a week of being there I walked into a gun store and found the used Marlin 39a I had been looking for. $185 later I was out the door with it. After shooting it I decided I should have just bought a new one since it would have been worth every penny.