We did an update last week with some improvements in performance. We have basically speeded up the loading times while opening and switching between sheets. The first time there may not be any difference, but subsequent load times should be faster. We will be improving the performance even more in the coming updates.

We also now support comma (in addition to semicolon) as the argument separator in functions and exclamation mark (!) as the operator to refer to other sheets (earlier it used to be only dot) . These are the operators used in MS Excel, which we failed to support earlier, but now we have supported them.

Also we are working on more features which didn't make it to the last update. You can expect them in the next update coming soon.