Hi Paul,
Ah use Paint.net a lot. Not as much as ah used tae. Been using the free Zoner Studio 17 more, in order tae learn it properly, mebbe use it tae replace Picasa since Webalbums was ditched by Google and Picasa will no longer be updated (though many users have asked Google tae make it open source and turn it over tae current users). Paint has a really easy resizer and the adjustments and artistic effects are very subtle, not overblown technicolour like some programs. Ah think Paint has many more powerful apps/add ons than Zoner and the forum is about the most helpful and instructive ah've come across.
Ah'll probably go back tae Paint once ah sort the albums and cataloguing in Zoner, it is that good, especially for free. Just done an update as we speak. Ah recommend it .
PS ah found it more intuitive than either Elements or Photoshop.