Here is my personal take on it...
I own Lancers, Pmags, and others, but most numerous are aluminum magazines with Magpul followers as well as US military knockoffs with the reversed follower. From my perspective, all of these magazines are equally susceptible to loss and breakage. By signing up with vendor email lists and paying attention to sales, you can usually buy any modern magazine for under $10 apiece; some shops in good areas will sell them for less as a daily price.
For my money, and yours, a patient buyer can get 2 to 3 magazines (including L5s) for the street price of an L5 AWM. AWMs themselves are also subject to bulk deals and sales. The more you have, the better prepared you are for any of them breaking for any reason.
If you are absolutely dedicated to having only one kind of magazine in your reserve, pick the type that you can not only afford, but afford to "replace in advance."
All above is practical hogwash though...
If you're obsessive about matching your furniture (like my brother), stick with Pmags, Tango Down ARCs, etc.
If you're a wannabe professional photographer (like my brother), go with Lancers... as they tend to be the prettiest and most frequently used by Oleg Volk, among others.