Yes, they are. Played IG or SM vs. Eldar lately? No? If so, you'd see how absolutely obscene Rangers are. Even with successive tonings-down, Rangers remain a severe issue and definitely warrant further discussion and analysis.
The reason Rangers are currently overpowered, for the unaware, is quite simple: They have excellent range and reasonably high damage, ridiculously high morale damage, and access to both Fleet of Foot and Infiltrate - and all these on a T-1 unit with 100% accuracy and negligably less HP than a Scout (and with nearly double the squad size).
Individually, this unit wouldn't be quite so bad - but it's complete rape on several maps, and is particularly brutal against SM and IG, due to how effectively Rangers can lock down any attempt to expand your econ. Any detector attempt from either race is easily dealt with, either via FOF or blatant chip-shotting, and if you try sending a commander against them, the Rangers will break it in one volley, since they can manage to suck off several hundred Morale points in a single salvo.
The proposed fix is quite simple: Delay Ranger infiltrate until Tier 2. Your thoughts?