I didn't want to overload the user interface with cryptic switches that 95% of the users will not use. I think, I will add an "expert mode" in the future that enables all these things. Right now, you can set the solid flag with two little workarounds (one for rar, one for 7-zip).

Ah, I like the sound of "expert mode" :)
You're probably right, I guess solid would be considered one of the 'cryptic' switches.

This is a very useful utility! I would buy it in a heartbeat except for the inability to set some common switches like solid archiving in the GUI. Otherwise, great work!

There will be a GUI for all the extra switches in one the next updates later this year.

Thank you very much! To show my appreciation, I just bought a license.

:-)) Great, thanks!

It's a year later and I don't see the expert's mode in current version, unless its hidden and I just don't know where to look. I'm using the .rarrc file to set solid as well as a number of other options, which I'd do anyway for use from the command line. However, it would be nice to be able to override these in the GUI when appropriate.

Also, I notice that when setting the compression mode, it assumes rar will operate with -m3 and so does not seem to specify it. If I have -m5 set in my .rarrc, I can't get normal compression from BetterZip, but can get faster (-m1) and none (-m0). If you just pass -m3 for normal then the selection in the GUI should always override the .rarrc and produce the expected results. This probably doesn't affect a lot of people, but I have my .rarrc setup for maximum compression to ease cli use.

The expert mode is not done yet. And it will also take some more time, but it's going to be in the next major version.

I'll add -m3 for normal compression in the next update. Thanks for the hint!