I find Python to be one of the least worst languages. It took some difficult weeks to figure out how to build and package, although, to that end, PyQtDeploy came along at just the right time. It's already in the Mac App Store.
Slow and steady with the addition of features over the last few months (http://bonhardcomputing.com/category/news/) and how does it compare to Transmit!? Transmit is an FTP app; Truck uses rsync-over-SSH.
Just append aliases to .bash_profile? E.g.
alias connect-amazon-example="ssh -i ~/.ssh/amazon-example-key.pem [email protected]"
Then just 'connect-amazon-example' at the terminal?
15 years is a long time. You're giving up a large amount of freedom right there. The DoE will still be there in 12 months if SV doesn't work out. I'd do it that way round.
The outlook is much better in 2017 than it was just a few years ago. Another +1 for PyQt. I wanted a native Mac look and you can get get pretty darn close with Qt. I've also used PyInstaller, which is superbly well documented.
As far as speed goes: Transfers: ~1000s times faster (thanks to Rsync as fimdomeio says); Browsing: ~10x (thanks Paramiko); Deletion: ~100x (SSH/rsync beats SFTP recursion).
Although one day I am going to write a FUSE/driver that implements all this and avails it for SSHFS, because it's hard to beat that Finder integration...