I ask because I own both Ledger and Trezor products and I am wondering if I should upgrade for security purposes. Are Ledger and Trezor products inferior because they require to be plugged into the USB? When does security become paranoia?
It will be good to check this below:
Hardware cryptocurrency wallet manufacturer Ledger has discovered a vulnerability that affects all of its devices and can lead to users losing their funds, according to a report released on Saturday, Feb. 3, 2018. According to the report, а “man in the middle” attack can be performed when the user attempts to generate an address to receive bitcoins to their Ledger wallet. If the computer that is used in this process is infected by malware, the attacker can secretly replace the code responsible for generating the address, causing “all future deposits to be sent to the attacker.”
There have been some vulnerabilities that were reported about trezor too at one point in past time. But, many hardware wallet scam victims were scammed during phishing attempts.
So far you do not have any issue before with your trezor and ledger nano, you do not need to bother yourself. Just make sure to be careful of malware.