Those are marketing numbers. What you are referring to is a vendor-neutral thing.
All you need to know is that MR33 does 2x2:2 and MR53 does 4x4:4
Then you can use something like this to compare
http://mcsindex.com/or this, same information but it includes the new 802.11ax (Wi-Fi 6) MCS rates
https://www.semfionetworks.com/blog/mcs-table-updated-with-80211ax-data-ratesRange isn't a value that will mean anything because it is only usable in a theoretical free space theory world kind of scenario. Otherwise, your going to get very different results if your in an office with 4 wall between you and the AP, is the door to the office your in open? Are you tilting your phone sideways, and more importantly what does your phone support (hint - its not higher than 2x2:2). There aren't really any clients in the wild that even have 4x4:4 capabilities, however having the extra antenna does in theory help with diversity/MIMO/spacial multiplexing etc.
Best case lab scenario, with a theoretical client that supports 4x4:4 is that at 20MHz, that client on the MR53 would get a data rate of 346.7Mbps, and on the MR33 it would get 173.3Mbps.
MR53 is 'better' in the sense that it has more streams/antenna and better CPU/RAM capabilities as well. This comes at a cost (financial) of course. I personally prefer the MR42 which is a nice middle ground on price and its capabilities (3x3:3)