The capacitor discussion should probably go elsewhere...
Matching values and other parameters when talking about coupling or signal filter capacitors, e.g. in the signal path, makes some sense when trying to get two or more channels to behave identically. Power supply decoupling ("filter") capacitors are usually common to both channels and even when not the circuit will (or should!) have decent power-supply rejection so it is insensitive to minor differences in values.
You have to be careful buying a bag of parts expecting to measure and match yourself. You can usually find some towards the end of the tolerance bands, but in the middle the well-matched (tight-tolerance) parts have probably already been selectively removed through manufacturing screens. If you buy a bag of 10%, 1 k-ohm resistors, expecting to match some to 1% at 1000 ohms, there may not be any in the bag. Why? The manufacturer already sorted and pulled all the 1% parts to sell as 1% parts. Ditto the 5% parts. So the 10% grab-bag probably contains a lot of resistors that are about 5% to 10% off the absolute value, e.g. you get a bunch of resistors ranging from 1050 to 1100 ohms and 900 to 950 ohms, but none in the 950 to 1050 ohm range that includes the 5% and 1% parts the manufacture has already screened and removed (to sell for more money due to their tighter tolerance, natch). What you can do is match a few to 1% relative to their value, so you may find a 915 ohm resistor you can match with a 920 ohm resistor that achieves 1% matching but is not within 1% of the 1000-ohm target value. That is good enough for some applications.
