That's good! And completely valid. You should give them all a chance; while some are better than others I don't think there's a bad job in FL right now. Not a lot of people with familiarity with the game play RDM in FL, so wisdom on the job is scarce right now. That said, it's nowhere near as bad as people make it out to be.
The first of the two major downsides of RDM is the lack of accessible instant casts. The other two casters have spammable instant spells you can throw out on the move, which is really important to your overall contribution, especially on the hunt. RDM can only do that through dualcast or spending metre. The other downside is, as mentioned, RDM's melee while combo powerful can be difficult to use in FL. Unlike actual melee jobs, RDM don't have that 30% DR. Even with the shield on Engagement it's very easy to die extremely fast in FL if a 15k HP squishy gets cheeky.
All that said RDM has a lot going for it. Dualcast helps a lot with its mobility and flexibility. Being able to reposition while you put out your strongest spells is huge, and the ability to proc it with Vercure and stuff is great. Also, the CC RDM gets is amazing at chase. When you get better at the job you start to get an idea of when you can pounce on enemy battle highs when they over-extend or retreat, locking them down for an extended period of time.
While it can be difficult to use the melee combo, it does still come up often enough in small engagements. What is more is you can do the combo sequence on something like a tank or melee that has over-extended, adjust your target, then drop the Verflare/holy and Scorch onto something in the backline; with BH and Phantom Dart this is practically two-thirds of a ranged DPS HP bar just gone. Even when you can't use the melee combo, Enchanted Reprise is a spammable 2k damage 1.5 sec GCD death machine that's great to throw at weakened targets. With how fast you can build Mana this isn't bad at all.
When everything is settled, RDM tends to not perform as well as SMN and BLM in terms of numbers. It's not a bad choice if you want to play DPS but you think your alliance could use a little backup healing or additional lockdown. It's just really hard to play right now to its full potential, and when you do, it's okay but not particularly stellar.
Signature is from the opening of Etrian Odyssey Untold: The Millennium Girl. Fun series.