I've never had a hinged floor plate open accidentally, so can't see any "reliability" reason for choosing a blind magazine. Blind magazines are certainly less convenient.
I have a Sako M85 .375 that I like a lot, it has a detachable magazine that holds 4, does not protrude below the rifle, can be fed from the top, the magazine latch locks, and I like the ability to load another full magazine in about three seconds. A very good system, not necessarily better than a hinged floor plate, but not inferior either.
Not all detachable magazine rifles are as well designed as the Sako. Single stack ( not staggered) magazines usually feed well but have limited capacity or protrude below the receiver right where your hand goes when carrying. They have to be removed when loading, and often are a feature of rifles with a very small opening in the receiver. Not ideal for dangerous game in my opinion.