Wood filament

Does the wood pla warp in the sun or heat like regular pla

as I've never had regular pla warp in the uk sun - no idea.

But the good stuff (colorfabb) has almost zero shrinkage during printing and will happily print on a cold bed.
But as it's just wood dust mixed with pla - so the thermo behaviour can be taken to be the almost identical to pla.

Do you use the steel or other harder nozzle with wood?

Wood clogged my Ender and Sidewinder with the .4 nozzles, I switched to a brass .6 nozzle and it printed just fine.

wood is softer than brass so any extra wear on the nozzle is minimal and not really worth worrying about.

The biggest issue with wood filament is that the cheaper brands use larger particles of wood and that can clog your nozzle.
I've used three brands and the colorfabb and ooznest work almost as well as normal pla. The ooznest even has minimal stringing and comes on lots f different 'wood colours'.

Very cool. My i3 Mega arrives today. I have 2 spools of PLA and 1 PETG coming tomorrow. Anything special to know about PETG?

oh yeah.
It prints hotter and a lot slower than pla.
Active cooling should be set to low or off.

Succesful Settings seem to vary considerably between makes.
So to a certain extent it's trial and error.

Get it right and it can be incredibly strong. Get it wrong and it can almost fall apart.

I avoid it :-)

Lots of people round here who use it regularly though. So hopefully they'll give you better tips.

PETG requires a bit more squish than PLA, although there is a sweet spot that works well for both. Also, depending on the print surface, you may want a release agent. I've seen where it has stuck so bad to glass that people have torn off chunks of the glass bed, same with a smooth spring steel sheet. Textured sheets seem fine without a release agent, anything else, lay down some glue stick or some windex.