Quite a few people mention that ones with bigger tweeter/midrange sound better.
If you compare 2 models "Raw", probably.
The bigger woofer will allow more bass.
But is that valid when you compare the 8351 alone vs the 8341 + sub ?
For more or less the same price, in your case, I'd go for the 8341 + (1×) 7370.
(For your use, a 7360 would be enough. But I like it loud, from time to time, and I know I'd want to fill the room at some point. A level similar to my current 1032 is perfect.)
It may even be louder than the 8351 alone.
(And, after all, your thread is titled "Convince me not to buy the 8351b", isn't it ?)