a mini is a mini and a full size HomePod oh heck, there is no comparison. However, some will say 2 minis are good. I say that compared to a mini, it's day and night.
It is interesting that they also preferred the Studio to H2. Brian Tong said the same thing in his comparison. That being said, it came off as a mad Android/Spotify user that is upset it didn’t natively work with their stuff. I have an OG and a mini and they are not in the same league for SQ. I can’t imagine that H2 would be dramatically different in that respect.
As far as Apple’s original tuning on the OG, many users said it had too much bass. That was probably the main reason for the re-tuning. The issue with a small speaker is that some will have it sitting on a table and some have it shoved into a bookshelf. Apple should allow more EQing of the HomePod which would make it easier to adapt to location and taste… above and beyond their own calculation.. Audyssey for example, allows you to override their measurements…especially with their app.
all two channel speakers essentially create a center if they are connected properly. However, a center channel still makes a difference. I realize the Sony speakers do a good job with DSP, like many receivers, but they still allowed for using some Sony TVs as the center to help… with mixed results depending on the TV.