IMO a properly flared line mated to it's proper fitting is a hard situation to beat. I purchased a quality hydraulic flaring tool and I don't regret it one bit. It makes nice flares and you can get to hard to get areas with it to repair rusted or pinched lines. The compression fittings to me in a brake system (other than air) with steel lines is just asking for problems to me. Like you said the higher quality fittings hold, but they're also using high grade stainless line too. Not some cheap mild china steel that will crush when the high quality compression fitting is tightened.