FPGA is that any good?

[kiara]

hi,
i am taking an old subject back alive. (hope for it at least)
since hashcat 3.0v started to support fpga i wanted to know more about this cards and his performance.
i've read most of the articles about it on the forum, from my understanding back in 2012+- some one asked about it here and here and here  , the conclusion in short, atom & epixoip answers was the fpga are good against single algorithim like DES and Bitcoin, bruteforce a single hash and electricity worth. multiple attack modes, multiple hashes, or multiple algorithms and the card was unflexible..
now the question.

why does it fall on multiple hashes,attack,algorithim? (please mention all the detailed.. like really everything)
can u mention other single algorithim beside DES and bitcoin?
what is the different between a single algorithim and others?
why it is not flexibility? what make it so unflexible? what u guys ment by saying it?

xilinx sales fpga and i think the latest of their product is 
http://www.xilinx.com/products/silicon-d...-plus.html
and
http://www.xilinx.com/products/silicon-d...scale.html

i have a benchmark of their LX150 spartan 6 and the result are quite low in some algorithim compare  to gpu. but the spartan is for lowcost and old.

thanks.