I love DRG as a fun class to use and prefer to use it over almost anything else but there are lots of people who still think this is 1.21 and think DRG has a huge accuracy issue (which it doesn't anymore) and you may have a problem with under-skilled parties preferring a BLM. Blm is stronger assuming it's not a fight you actually have to move around in, but in my opinion and a lot of others, it's a totally snore fest. Stand here, trigger skill, cast thunder/fire, rinse and repeat.
But if you really like DD I'd suggest you go for Drg and Blm as well as Mnk and Brd, they're all fantastic and it really just boils down to play style. It's not that hard to level to 50 once you get a hang of leveling so you should try to level them all to 50.