Bookworm. Although I'd agree with you that the R/T is being increasingly cluttered here's a typical example of why we need type....arriving aircraft checks in with approach but no type confirmation. FPL says ATP. Vectored into the sequence and....Out of the clouds pops a Jetstream 41! Oh dear! There's a vortex issue with the preceeding heavy. You'd be surprised how often this sort of thing happens with no notification to the destination. I can also remember a type issue with Gatwick where a B733 was planned and not spotted for a change to B737. Apparently the extra wingspan caused an issue with Gatwick being on 26R and use of the taxiway.
Spiney