True. His voice as changed quite a bit.To me it's just not Zep without Bonzo but the biggest problem with other drummers is the drum sound. You need BIG drums with a ton of ring but none of the fill ins have used this sound.
Also, Plant simply cannot sing those old tunes anymore; his voice has changed too much and he doesn't have the upper range.
There is no way they will be able to live up to the hype; I hope they don't do it.
I admit I haven't paid that much attention to Post Zep Jimmy, so this is something that is new to me....the real problem here is jimmy page. he is totally burnt out, and hasn't been able to play guitar for decades. with enough commitment, and enough rehearsing and woodshedding, he might be able to re-learn the instrument, but from what i understand, his brain is completely fried.