Guys, can we please keep the topic on Dragon-types outside of direct comparisons please?
Anyway, in regards to the discussion:
Personally, I don't think Dragon-types are over-rated. To be over-rated means to receive loads of hype when they're not actually good. The thing is though, dragon types are good. Latios and Garchomp in particular are huge in the current VGC metagame - few Pokémon can withstand a Dragon Gem boosted Draco Meteor from a Latios. Dragon-types having very few weaknesses (only Dragon and Ice) and a fair few useful resistances only helps matters.
So no, I don't think they're overrated. Overpowered though? Possibly.