Stefan:
I recently saw that RandomControl now offers also a learning edition of Arion 2.
My questions, if you don't mind, are does Arion's license allow you to install it on two machines,
because i would like to set-up my scenes on my iMac (Win XP) and later render them on my Notebook (Win 7), which outperforms GPU wise my iMac.

I don't know exactly their pricing & licensing,better to contact them to clarify your doubts
anyway Learning Edition allow you to use all GPU's of your system
Network rendering NOT allowed
max resolution:1920x1080
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Stefan:
Can the preview rendering mode, which i saw on a youtube demo, be turned of, like working in Maxwell Studio, prior rendering

Arion is a real-time application,this mean that just after you loaded the scene render starts immediately.
You can't quit the render,save the framebuffer and resume later for more computation(like Maxwell and Fryrender)
The preview mode is what you get,just choose output size and format so it's a WYSIWYG application
Setting camera focus and position,assign materials,all done in the preview window

You can choose which devices will be involved for computation,which videocards and how many Cpu's cores
Being a CUDA-BASED application you must have an NVIDIA card,if you have an ATI you can use only CPU(than you loose all speed benefits fo hybrid calculation)
They suggest to use two videocards:one for computation,other for UI and navigation.That's the main thing!
Normally you got just one videocard,this one must handle UI+navigation and also all computation that Arion require
this mean a general slowdown or a freeze in all UI operations(open a new window,navigate on Internet while Arion working,change a material,moving the camera,etc)
you can switch Arion in PAUSE and do all you need,or change your scene settings,but sometime changes you made are not updated in the preview window
this depends by your videocard and the amount of video-memory(I'm experimenting this with my GTX 460 -1Gb video RAM)
if you plan to manage heavy scenes or render at high resolution you must have a videocard with at least 2Gb video RAM and the highest number of CUDA-CORES
be careful when watching demos on Youtube:you see Arion performing in real-time but they don't tell what hardware they are using...
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Stefan:And last but not least does Arion 2 comes with a (good) material library?

Materal library comes in 12 sections:

AUTOMOTIVE:6 carpaint materials
CLOTH:2 satin materials +3velvet
DIFFUSE: 7 colors
EMITTERS:14 emitters (D50-D65-tungsten-studiolamp-flash-white-candle) IES are supported
FROSTED:5 variations of frosted and smoked glass
GEMSTONES:11 different gems(amethyst,aquamarine.topaz,etc.)
LAMBERTIAN:7 colors
LIQUID:6 (bordeaux wine,water,oil,ice,etc)
METAL:5(aluminium,copper,gold,mirror,silver)
PLASTIC:19(rubber,plastic,marble)
SSS:12 (beewax,rigatone pasta,acrylic etc.)
TRANSPARENT:12(dispersion diamond,transparent plastic,smoked glass,etc.)

They have improved materials behaviour from Fryrender to Arion and i can say that you got top quality
Metals are not the best area (it's the most difficult stuff to replicate in all render engines,unbiased or not)
Architecture and interiors are best fields for Arion,sun also works good for outside scenes
Best of all if you are a Max OR XSI user,so you can manage all setting inside them using LIVE plug-ins
i get benefits using my old FRY-C4D plug-in to manage the scene than export all and open in ARION
i think that is slightly difficult have the standalone version and manage all settings inside arion after importing as OBJ
in that case you can't have full control like with the plug-in..no doubts you must have a strong videocard

hope this help little more

M

Thank you very much, m-dynamics,
for your thoroughly explanation. It's very helpful for me and much appreciated!
It would be cool if Random Control could release a demo version,
so that one can try out by itself, to see the performance on a given machine.

Hopefully Maxwell 3.0 will bring GPU rendering to the table too...

Thanks again for your help!

Best regards
Stefan

..your welcome Stefan...
few months ago they gave a demo -version and some ready-to-use scenes for testing,suddendly changed a lot of things:
quit Fryrender,no more support for all plug-ins(MAYA-C4D MODO-SKETCH UP-RHINO-LIGHTWAVE etc..)new pricing and licensing
Fryrender is still on the top with Maxwell,give faster results but belongs to a small company
this means an heavy work for the programmer to update all plug-ins to the last releases(like in C4D,they changed all from 11.5 to 12)
if i remember correctly,i have read on their forum in the past,programmer that worked on the plug-ins left the company
then,probably, they decided to continue development Arion without supporting all plug-ins, just MAX and XSI
they give - Arion sdk -for sale if someone want to develope a Live plug-in(i hope that this happens in future)
you can imagine how fast will be in the next future render with newest CPU and GPU's getting an unbiased quality
so you also will render animations to that quality,but no live plug-in,no animation
maybe you would consider which application give these features,before buying(if you need that features)

M

To bad that they cancelled the demo. It would help me a lot to have a demo to decide if i should buy or not.
Well, maybe they do it again in the future (hopefully).

Regards
Stefan

There is also Marmoset Toolbag: http://www.marmoset.co/

Here's a link to a preview of new GPU render coming with the next public Thea version: http://www.youtube.com/watch?v=MZUKi8tlycs&feature=player_embedded