If you are just wanting to rip files from a game. I use MagicISO or just mount the iso file with a virtual drive sometimes to extract. So it really isn't any better for extraction just easier. But for reinsertion. I only use UMDGen do to the file allocation and CRC/LBA stuff associated with the games I am working on. There is also another good program called CDMage. Found out about it when reading up on Cless's TOP PSX translation. But unlike UMDGen, it overwrites files without the option for a backup. If you use it, make sure you have a copy of it backed up elsewhere. I have screwed many iso up till I realized this.
Simple answer:
Extraction - Use anything that can get your files
Insertion - Stick with UMDGen for the ability to specify file order due some games breaking if not set up just... right.