I try and have tried most of the rendering engines compatible with Sketchup out there and I permanently look for new ways that could improve the architectural/interior design visualization workflow.
For several years Vray has been the best (for its great image quality) but, the latest version of Light up is turning out to be a more convenient and a more powerful tool in my opinion.
The capacity to fly a rendered model (using the GPU unit) right from inside the Sketchup window is changing the design workflow in a very very positive way.

And just like Sketchup is, Lighup is really easy to use.

You won't get all the subtleties that Vray has (too complicated anyway I think) but the ease of use and the real-time / in viewport “Tour tool” capacity is absolutely the way to go: I find myself producing now much more finished videos, stills and flythrough than I ever did with my 1000$ Vray license…

You should give it a try! For less than 200 $US, you will see that Lightup is an essential and revolutionary extension to Skecthup.

This is not that giant you know; I frequently work on files that are twice this size.
Many different things could provoke that behavior though, first troubleshoot method would be to do the following:

1. Open sketchup (new file, not your big file)
2. disable VRay plugin (go to window/preferences/extensions/ and there, uncheck the Vray plugin).
3. Close the program.

Now try to open your big file again and see if it opens up.

How come sketchup is so slow and unresponsive under mac os 10?

I get awesome performance under windows 7 (64) but real bad performance under mac os 10 (Snow leopard)

My machine is a Mac pro 2008 with the nvidia GTX 285. I have mac os and windows 7 on 2 separate HD...

I have been trying to figure this out for a while... Does anyone know if there is a way to explain this/ Fix it?

Just posted my report too...

Same here: copy paste to V.7, do the drape, copy paste back to 8.

I actually find myself not even using V.8 at the moment.

We need to get this resolved somehow.
What is the best way to get inputs from the Sketchup support team on these issue?

Drape operations that run fine in Sketchup 7 but consistently crashes in Skecthup 8??

Go figure...

I too had performance issues with SU 6 under Leopard (Slow panning, unstoppable orbiting, difficulties selecting object...)
Turned out the Logitech mouse was causing the problem. Movements and selections are much better now that I have re-installed the mighty mouse.
Now, I still get faster, smother and nicer (antialiased line) performances under Win XP (same machine with Boot camp drivers).