Let's start foam tips vs silicone tips. Yes,
foam absorbs more sound (vs silicone that reflects it), but it also alters every headphone you give it and creates a darker tilt to the headphone. I absolutely hate this about foam tips,
granted properly prepping the tips for insertion helps, it doesn't fix the issue entirely. If you prefer a darker sound, this will do it for just about any headphone. I'll agree that they are much more comfortable and isolate much better (thought it comes at a cost since they need to be replaced more readily than their silicone counterparts). In terms of SQ, foam absorbs mids and highs, silicone reflects, that internal ANC kind of minimizes both by just canceling it. All three will have their own effect on the SQ. What's best? Depends on your needs. Want something longer lasting, go silicone. Want more isolation, foam. Want a darker sound, foam. Want a brighter sound, silicone.