[sunnybob]

I have the JET 12" benchtop. It works well for me as I have limited space. I bolted it onto the top of my tool chest base unit so its on wheels and I can move it to one side. All the heavy tools stop it from being top heavy.
I can plane 8 ft boards all by myself. longer boards would need a helper (or table supports).
i dont have any problems with the knives. They are easy to remove and replace and I have found a shop that sharpens them and I dont even have to to go there, they travel by courier.

The really BIG issue with these is the NOISE!!! If you live close to other people you will need to time your usage when they are not in.

 

[sunnybob]

Blade wear depends entirely on how much you put through the machine, and of course how hard the wood is.

You could plane softwoods all day, but try a few board feet of bubinga and those blades will start to dull quickly.
And if youre using scrap wood, just one staple or nail will destroy them.

I only use mine for hobby usage, I dont make any furniture or large runs of planking. For me, this machine works very well.