There were 4 studio albums after Cozy left. One before he joined.
As good as Down to Earth is (and it's my favorite Rainbow record) Bonnet struggled live with the Dio stuff. Turner & White managed to sing the songs well... If you've ever heard Bonnet's take on Catch the Rainbow (and i have a feeling you probably haven't) then you'd understand. It's fucking appalling.
With all respect, it seems you're coming into this argument without much actual knowledge. You haven't heard all the stuff you're dismissing, you're certainly not giving examples of concerts you've heard (attended??) to back up your points.
The Boston show from the DTC tour features Turner delivering excellent versions of Catch The Rainbow & Love's No Friend... The Kyoto & Hammersmith recordings from the SIUA tour has White delivering beautiful versions of Temple Of The Kings... These guys could sing the catalog beautifully, powerfully... Bonnet shouted it... Shit, he even struggled on some of the DTE stuff!
As I said. I'm a Rainbow fan... It seems you're not... more a Powell/Dio/Bonnet fan. There's a thread elsewhere on these boards where we were asked to list our fave Rainbow records... I think mine were listed like this...
1) Down To Earth (Bonnet)
2) Long Live Rock ' n' Roll (Dio)
3) Bent Out Of Shape (Turner)
4) Rising (Dio)
5) Straight Between The Eyes (Turner)
So hey, Cozy, RJD & Bonnet feature in the top two, but I'd put BOOS waaaaaay above Rising. As I said though, when it comes to LIVE STUFF, you have to consider Turner & White... They are after all the only ones to take on the whole catalog & do it well.