There are numerous FTP clients available for Mac and each of them claims to be the best because they have the most features and are the fastest.
CrossFTP is an average FTP client, but after trying a lot of them, not one I can't live with.
First thing is : it's Java based. While this makes sense for the developer who can offer a multi platform product, Java is about the slowest environment you can think of. And to install you need to determine if you're running Java 5, 6 or 7, download the correct version... only to find out that, after the numerous leaks in Java's security, Apple disabled it, so you probably will have to install Java. Thus, CrossFTP is NOT WORKING out of the box in some (most ?) cases.
Second thing is : it's working nice with Dual-Pane interface. But it lacks one feature that other FTP clients offer, even sometimes for free. That is the ability to transfer files from remote site to remote site. Of course, you can always mount a remote FTP server as a disk in MacOs. But doing this will end up with several "invisbible" files dropped in every opened window... Not really nice. Transmit can do "remote to remote", as can Forklift.
So all in all, it works, transfers are rather fast but being Java based it not as responsive as it could be if developed natively for MacOS. I think I'll stick to forklift, Filezilla and Cyberduck.