You can't buy too much subwoofer, unless you get to the point that something physically does not fit into the space you have. You can turn down a large sub and make several types of adjustments depending on your system to make it transparent, but you can never turn up a sub that is too small and underpowered. My advice is always to buy the best and largest sub that you can afford, and then be happy for a very long time. There is no such thing as "pairing" or matching, or other old wives tales applicable here, it's about the bass. So many myths and half-truths out there about subs. A sub can both supplement and support the low end of almost any system out there, no matter how 'high end" or basic the system may be. I've had the pleasure of owning a large variety of subs since about 1986 with various systems. Everything from custom-built cabinets with separate amps, to multiple subs in my main room currently. Some that have been celebrated and some that get a lot of questionable reviews. Not once have I ever said the sub doesn't belong or that I spent too much money. Always read the specs and performance details, as that is all that mostly matters. In-house demo would be great but is impractical or impossible for many people. The typical showroom is nothing like your house, so the specs tell you most of what you need to know, and after that it will be placement and adjustments for your space. You are not listening to a sub for the most part, and the adjustments and ability to blend into the system are what matters, which can be done with all of them. Just follow the advice to buy a highly rated, highly powered, and suitably large unit, or multiples.
Did you ever buy too much bass?
I talk a lot about bass and integration of subwoofers in a system and I realized that I need to hear more about the experiences auidphiles have when they go buy speakers and put them in a room. Did you look at specs? Did you audition in the home? Did you end up with too little or too much bass compared to what you were expecting??