Thank you for your responses.
What wonders me is that all the electrolytic capacitors are rated as high as 400V! Do they really have to be that high? Doesn't 100VDC suffice? (pretty much all hifi-shops here sell only max 100VDC bipolar capacitors)
All the polypropylene caps (bypass and the ones in the tweeter network) are average SCR/Solen capacitors, could it be worth upgrading at least those in the tweeter network to something better, such as Mundorf M-Cap Supreme? I'm not saying that the speakers sound bad, just that because the cabinets and drivers are of first class, there must be some room for improvements
Does it matter if I select a smaller/larger value for the bypass caps, as long as the total capacitance stays the same?