I am only working on motherboards and LCD monitors.

1) Are the Rubycon MBZ and MCZ interchangeable? From what I have read here so far the MCZ is the best one but are the MBZ's good enough?

2) Does the physical size of the capacitor matter as long as they physically fit?

Two examples of what I am looking to do:

A) Replace Nichicon HN(M) 820uf 6.3v 8mm x 20mm with Rubycon MBZ 8mm x 23mm

B) Replace Nichicon HN(M) 1500uf 6.3v 10mm x 13mm with Rubycon MBZ 8mm x 20mm.

Thanks for any help!