There are no limitations built into Stardraw and it can import huge AutoCAD files as shown by your customers example: The file has nearly 600,000 entities such as lines, circles, text etc. etc. on 180 Layers. It imports this file very well and draws them very quickly.
The question is, how can your customer improve the speed at which he works on the drawing?
There really are only 2 possible solutions:
1. Decrease the size of the file by either deleting unused entities or temporarily turn some layers off that he isn't working on.
2. Increase the speed of his machine by getting a faster processor, faster graphics card or more memory.
Stardraw really has been optimized to draw very, very quickly and there is not going to be a major update soon that will make drawing an order of magnitude faster.
To be honest, we have had no-one else report any problems of Stardraw being slow and if he tried loading up his file in any other piece of software, he will experience exactly the same if not much worse problems.
David Snipp
Stardraw.com Ltd