I would probably do the same. But I've serviced a few of the Powermore engines and they seem OK. Only one had an issue and that was caused by someone putting on a fuel filter that was over sized. Sometimes you run into things like component only servicing IE like a whole carb rather than parts. Much like the ChiToro engines. They all seem powerful and good when they are relatively new. We'll see what the 10 year old models need...

Thanks for the comments. I went today and looked at each version, and the decision suddenly became more complex; the Craftsman was as-expected but the oil drain was in a pretty bad place. But the Murray with the Intek did not have an oil filter. The picture of the engine on the B&S site shows a filter but there was not one to be seen on the engine I looked at. This could mean that its splash lube only, with no oil pump, or possibly has an oil pump but no filter.

So at this point I'm leaning toward the 420cc engine because it has full pressure oil and a spin-on filter.

Just did more research at MTD. The Powermore engine has excellent features including forged crank, iron cam, ball-bearing mains and a cast iron sleeve. Together with the full-pressure lube and filter, I'm definitely moving in that direction. Also found a review on You Tube that was encouraging for the mower in general.

My rear-engine Craftsman is a 1992, and the Tecumseh engine has been trouble-free, still starts first time every time. I have only had to replace tires and belts on it.

Both machines are compariable , go with price point and warranty along with local service agent reputation .

Still looking at them and just discovered there's a Cub-Cadet version with hydrostatic drive. Also looked at the 'Troy-Built' version at Lowes which the ad said has a filter, and it doesn't. Its the B&S 344cc engine that a number of them have, and none of those I have seen have an oil filter so presumably there's no oil pump either. MTD must be making a dozen versions of this mower!

Okay, the 420cc engine is 15HP.

Cub Cadet also has the manual shift version as well as the hydro-drive. I've never had this drive, but I'm guessing you set the engine speed as usual and press the RH pedal to go - press more for faster, less for slower. Its $400 more and I'm thinking my foot might get sore holding that pedal down the whole time, so I'm not considering that one at this time.

So, I'm satisfied that I've answered my original question and I will be going with the 420cc engine; more power, commercial grade, full pressure lube and spin-on filter. Now I just need to find a deal!