I wanted to like this. I'm leaving three stars because it has potential.
I have Safari, Chrome, Firefox, and Opera installed on my Mac Pro running Yosemite 10.5.5. All the browsers are the latest versions. All work reasonably well.
I tried this browser and it crashed right off the bat. After two more tries it came up, so then I tried to download the user manual. Big mistake. Crashed again. I copied the PDF's URL into Safari and Firefox. Safari stopped downloading halfway and froze. On Firefox I got a message above my bookmarks bar saying that there was a problem with the PDF. I quit and tried again and after a long time it finally downloaded. I view and download PDFs in both those browsers on a daily basis (my online store creates PDF invoices for every sale.)
I then reopened Roccat but it wanted to download the manual again. There was no way to quit and the force quit dialog showed it as a red app, not responding.
At first I couldn't find the location of the preference file so I threw away the Roccat folder in Application Support, quit out of everything and tried twice more with the same result: deep freeze. I went back to preferences and tried viewing by date and found it! It's under ORG.Runecats, not com. Deleting that got me back to square one.
The default for saving the Fusedbar URLs should be NO. That would have probably prevented the browser from trying to repeatedly download the Roccat manual it was choking on.
Next I tried to import my Firefox bookmarks. It's a breeze importing Safari and Chrome into Firefox or the other way around.
Roccat, not so much.
I chose import in the menu, selected Firefox and there was no feedback (other than to ask me to close Firefox, which I promptly did). Is it working or not? I have no way of knowing. I tried Safari too with the same result. But after I quit and relaunched I did get a menu item with a folder containing a hierarchial listing of bookmarks and bookmark folders from Safari. Not too convenient. Computers and software are supposed to do the drudge work. Decades later and some programmers are still clueless.
When I actually visited a site the browser works fine and I like the little previews in the top bar but when I tried to bookmark a site the add bookmark selection in the bookmarks menu was grayed out. I was able to get the add bookmark in the pop up menu on the right side to work and it asked for a name for the bookmark but there wasn't any obvious way to cancel out if I changed my mind. Hitting the escape key actually typed an exclamation mark in the dialog box. Entering a blank into the window and hitting return made the friggin' dialog go away.
If this is version 5.1, I shudder to think what earlier versions may have been like.
Sorry, I gave up.
If you ever get this to work correctly, I would suggest calling the browser runecat instead of roccat (if you can) because Googling roccat brings up some German tech company first and runecat is just as good a name as roccat.