are hardware wallets really more secure than using online wallets such as the latest blockchaininfo ?
Yes. Any malware, even a keylogger which can't be detected by most antivirus programs, could steal your Bitcoin and Blockchain is notorious for phishing attempts. You also have to trust various aspects of Blockchain as a third party. With a TREZOR you can use several different wallets, like Electrum, with it which are all better and sometimes even more convenient than Blockchain with its broken fees.
There are no cases that I know of involving a hardware wallet's funds being stolen. Without the seed, it's impossible as far as we know. Even in the case of a 5-dollar wrench attack you can use a decoy passphrase which you remember in addition to the seeds.
A TREZOR is extremely secure, and for current purposes a Ledger is too, although there are elements which are not "ultimate" security, like how they advise you to set it up from a trusted device while TREZOR says that it's safe to set up with a compromised computer. In nearly all cases and for conventional purposes I would regard them as equal.
