Is it good to upgrade the crossovers in your speakers?

I found a pair of Sonics AS331 for 20 bucks. I looked around and found the usual audiophile snobbery about them online but decided since the cabinets and drivers were in awesome shape that I would give them a once over. I went in and found they are very well made, plywood, screws, and an actual crossover instead of some cheapo soldered in run of the mill caps and inductors. These were very nice! I replaced the caps with new/modern film caps, updated the inductors too. Tossed out the wiring and replaced it with some high quality 12ga wires and soldered them to the drivers. I sealed the enclosure and gave it a teak oil finish that made them look very nice. I was even pleased with the fact the lattice grill was real wood. I then hooked them up and cranked "It Aint Me" (CCR) and took a trip back to the 70's. I will be keeping these and no matter what the snobs say they sound great to me, look great and did not cost me a fortune. Go ahead and do your speakers if you want, some of us do not have the means to drop thousands on equipment, but if it sounds good to you then that is what matters. Besides it will give you a connection to your equipment that most will never have. 

I've always been satisfied upgrading crossover capacitors, resistors, inductors without changing the design/values.  Generally you get what you pay for, that's my experience.  

It's a tricky business no doubt because confirmation bias is a thing.

However, I was once asked to solder a friend's Celestion 44 cable connectors where they met the drive units inside the cabinet.

The existing tag connectors looked pitted and dull and after hardwiring the cables (after stripping and cleaning) the sound noticeably changed.

The tonal signature was still the same, but the pace and dynamics seemed to have been given a shot in the arm.

Even 6 months later, when listening to the the Beach Boys Sunflower double CD I could not escape the impression.

Thankfully, my friend Mitch was pleased with the results but I daresay there might be some who would prefer the previous more laidback nature of the speakers.

Just how they sounded when new, early 1970s would have been anyone's guess.

Anyway, I'd like to think all decent loudspeakers nowadays are either hardwired or use non tarnishing tags inside.

It can’t hurt you can always put old caps back in. Have you ever seen the crap parts in some of these expensive speakers. I’ve only done it to a couple pair of speaker and was a very nice improvement. New wire improves sound and outboard crossover made it easy if caps are bigger than original. Also makes it easy to play around with caps. I wonder if crossover not rattling around if cabinet helped. Modding both pair of speakers improved sound for me. It wasn’t subtle. 

Arguments about issues with sensory perception is problematic here, confirmation bias exists with all equipment, whether oem or modded,  it can always exist. To make blanket claim that all crossover modifications resulting in one hearing sound quality improvements are faulty because of confirmation bias is total nonsense. One could make that argument with every single listening impression posted on this or any forum. This would conform to argument that more expensive equipment is only superior due to confirmation bias, little or no correlation to better sound quality vs. the less expensive component. This is argument for not trusting one's own sensory perception. I could make the same argument in regard to the cheaper component, the value seeking consumer is biased towards the cheaper component.

Individual audio parts make their contribution to holistic sound quality of individual pieces of equipment. The savvy engineer or designer is aware of this and chooses his/her parts accordingly, you do see increasing use of specialized or upgraded parts in audio equipment. The naysayer will state its for marketing purposes, the listener will listen. The experienced listener remains ever mindful of bias, can also control for bias by return to previous configuration.