I've got a file. Whether I'm using it correctly is another matter.
Those logs took about an hour, total. That included about 10 minutes between them to roll them over after getting ~60% through the diameter at each section. Plus some short breather breaks (I was tired from the splitting and stacking earlier today - not used to this manual labor stuff, but getting there).
I guess I keep forgetting not everyone has a Stihl 046 with a 30" bar...
It does sometimes help to not cut all the way thru and then roll the log over, so as not to get your chain in the dirt.
It shouldn't be that hard to learn to sharpen if you do it before the cutting edge of the teeth are all mangled and chipped. Basically, you just follow the factory angles. Every once in a while you need to flat file the rakers(depth guage) also.
For firewood, I figure sharpening for each tank of gas, or even more if you hit the dirt. Logging I could usually go longer than that because you're not doing such an insane amount of bucking, plus usually not dealing with dry and dirty wood.
The saw should cut with minimal pressure and spit out big chips, not sawdust. If you're getting sawdust, then your chain is really dull.