Is it good to upgrade the crossovers in your speakers?

You can change everything in a crossover but the point is what do you want to achieve. More detail, different character?

The easiest part are the resistors and internal wiring and most likely what you refer as a sweet spot. Capacitors are costly, can bring a very good improvement but can also expose drive units. With wrong inductors it can get a real mess.

I agree with all posts above, leave them in factory form unless you have good experience in parts and building crossovers as not upsetting speakers' voicing.

Leave the poor speakers alone...jmo

It’s only a good idea if you really know what you are doing. Or just want to tinker and maybe learn and see what happens. Otherwise, if you have the right good quality speakers for you to start with, there is no need. The crossover was already designed and integrated by an expert. Also It is most likely that any changes one makes on any well respected speaker model will limit the # of potential buyers if you decide to sell, assuming one is ethical and properly transparent about such things

I'll be contrary here and say go for it. As long as you're not changing values of components you're not going to change voicing to a huge degree. And the best quality parts are only going to improve timbre, natural sound quality. You can always go back to stock if you didn't like changes. Understand exactly what sound qualities you're looking to improve, do your research on parts you plan to upgrade. Get it right and you're speakers will be much improved.

I agree with sns, you can always go backward if a change is not in the right direction.  There are a lot of popular choices of current production parts that are not necessarily the way to go; vintage parts should not be overlooked even if the common wisdom is that they go bad with time.  Some of the best recent builds I’ve heard utilized such vintage caps as Western Electric paper-in-oil capacitors, Cornell Dublier caps, and Jupiter caps (not a secret, as many of these parts are ultra expensive).  Internal wire can also be quite important and the right choice can be hard to determine; a builder I know basically chooses between various types of Audio Note speaker wire, including crazy expensive Sogon wire.