[duncanawoods]

I upgraded a couple when it was first released but a few basic features not supported so had to abandon the attempt.

I've tried copying a problem sheet to a new file and first impressions are positive. Thanks.

[hakanu]

As far as I observed, latest big update improved the performance of large sheets a lot. Plus, using chrome is also making some positive difference. However, copying and pasting large data is still a problem. Instead I recommend to use copy to option within google drive.