Santa's saying that what's "OP" to someone is different than to another person. Balance is another thing that falls into this "grey area", because it is again dependent on what each person thinks.
Its alright for someone with a space-time continuum warping sled to tell the rest of us we can't call something OP
--On-topic--
I wouldn't say that TE is lacking. It fulfills its design brief very well and other mods have moved into supporting RF with more content which is nice. I also agree that from a core tech modpack point of view, sticking with RF is probably a good idea for FTB. While there are a lot of big mods already working on RF, I hope that the modding community continues to surprise us with their imagination, and develop some more interesting addons (technomancy is an interesting innovation for example).
There are loads of mods that do not use the RF system and I am curious about their future in modpacks. I am very interested in an early/mid industrial era style modpack. With 1.7 making it easier to make modpacks, there seems to be a good opportunity to make a small themed pack along these lines. Is it ok if I ask people here what mods they would like to see in a modpack like that, and what are the pros and cons of having Rotarycraft and Factorization in the same pack. (If this is too much of a hijack I will delete this bit and quietly pretend it never happened).