The naloxone in Suboxone does nothing in real terms, it's a pharmaceutical company ploy.. buprenorphine is a partial opioid agonist, so will never feel quite the same as a full agonist, but less is more with it really - keep upping your dose doesn't up the effects in the same way. Also, at <2mg doses more is converted to norbuprenorphine with is a full agonist so you can actually get more from low doses providing your tolerance allows it.
Naloxone has a lower receptor affinity than buprenorphine, so it doesn't have any effect. It can be used in bupe ODs at very high doses, but in terms of Suboxone vs Subutuex you can ignore it entirely. Some people seem to find naloxone gives them a headache; not seen any research on this but it's mentioned on BL a few times. Could be fact, could be myth.
Bupe does block other opioids due to it's high receptor affinity (basically clings onto the opioid receptors more, and kicks off other opioids too which is why you get precipitated withdrawals, alongside the fact that it is only a partial not full agonist - so it kicks off the full agonist opioids and replaces them with a partial one, putting you into insta-withdrawal if you are physically dependent). You need 24-48hrs really to feel other opioids again - sometimes a good 72 hours. Any sooner and you may get effects but they are likely to be greatly reduced.
naloxone does have a pretty high affinity, it works in overdoses by kicking the opioids off the receptors (it is an opioid antagonist) but buprenorphine's is even higher.