Some highly credentialed pistolsmiths and end users swear by FLGRs.
Some equally highly credentialed pistolsmiths and end users swear AT them.
I understand the arguments, but my own experience (including watching a helluva lot of students with both) is that there is no significant improvement in accuracy or reliability with the longer rod.
It is, however, a pain in the butt (to varying degrees, depending on the design) for disassembly and reassembly.
Some of the two-piece ones have been known to break. I've had good luck with my FLGRs in that regard, and the long rod is not a deal-breaker for me on an otherwise nice 1911.
That said, though, if all other things are equal I'd rather have the standard "John Moses Browning got it right the first time" setup on my own 1911s.