I want to use this metric to compare 2 servers. I've looked at sys.dm_io_virtual_file_stats, but this is missing logical. Also looked at query_stats, but that only includes cached plans.
I think that what you might be after you may find in a different DMV:
select * from sys.dm_os_performance_counters
But pay attention to these
Counters like Page reads/sec appear to be cumulative. Which just blows my poor head. In that case it should be named like 'pages read'. So to get actual Page reads/sec you have to do smth like:
divide the counter value by amount of seconds since startup (you can get it by select datediff(ss,create_date, getdate()) as uptime from sys.databases where name = 'tempdb').