I am pretty sure these guys are going to try and fork the network to force Segregated Witness on people. They will fail. Ledger does support this minority chain. The private key is the actual address where you Bitcoins are stored. A recovery seed is a group of private keys that can be restored on most devices. The advantage of using a recovery seed is that if you accidentally send some coins to a change and delete the wallet you can recover the change address. Private keys are the most low-level basic way to retrieve your Bitcoins and recovery seeds are an encrypted 2 layer way to recover the keys. You always want the direct simplest way to retrieve your keys. If somehow something happened to the second layer and you had your private keys you would be able to recover your coins. Where if you only had the seed, that is now broken you are SOL. If you had your private keys you would not have to worry about what these ass hats were doing. You can have a recovery seed and have your private keys at the same time.