1 or 2 large UPS vs several smaller ones?

Hi guys,

         I was wondering, if one server room has say the following:

7 physical servers (host for VMs)

Several switches, routers, modem

Assuming space is not a constraint, what is the better UPS option:

1) Two large UPS to cater for whole infra

2) Several UPS for different physical stuff, like two for switches, and routers, two for servers

3) 1 large UPS for entire infra

Which one would you choose and why?

Thanks