This really depends on the application; but in general FPGAs are a good choice for small to medium volume software defined radio applications, including building correlators and beamformers for radio telescopes (casper.berkeley.edu). CASPER tools used to be a major user of Borph - it made the open hardware and software platforms easy to use to anyone that had experience with Linux; however its use got killed by complexity.
The biggest challenge for FPGAs is tools; the CASPER guys used Matlab Simulink; which works OK for small designs, but becomes challenging as the devices and designs grow. There are also a bunch of C to gates tools, Matlab to gates and Haskell inspired tools like Bluespec, and even some Python tools. In fact for the Berkeley CASPER group, as GPU through put improved (along with processing) and the size of the radio telescopes increased, it made sense to move to a hybrid FPGA+GPU backend processor.
We have used it to build a arb. waveform radar transceiver and a few other things.
Ofcource now one has the Xilinx Zynq 7K family which includes dual core ARM and tightly coupled Xilinx V7 fabric all on a single chip. Plus for a few hundred $$ you get a nice development board (www.zedboard.org) and a frontend wirless digital receiver FMC card - http://goo.gl/qCnJM
The biggest challenge for FPGAs is tools; the CASPER guys used Matlab Simulink; which works OK for small designs, but becomes challenging as the devices and designs grow. There are also a bunch of C to gates tools, Matlab to gates and Haskell inspired tools like Bluespec, and even some Python tools. In fact for the Berkeley CASPER group, as GPU through put improved (along with processing) and the size of the radio telescopes increased, it made sense to move to a hybrid FPGA+GPU backend processor.
For fun and training we built an ARM Cortex A8 (with or without GPU and vector processor) + FPGA platform called Rhino (http://www.rhinoplatform.org), with a couple of FMC IO slots for attaching ADC/DAC/Control etc then ported Borph and then linked up with the Migen project (https://github.com/milkymist/migen) to "simplify" programming and configuring the FPGA (https://github.com/brandonhamilton/rhino-gateware). We think it works great ;-)
We have used it to build a arb. waveform radar transceiver and a few other things.
Ofcource now one has the Xilinx Zynq 7K family which includes dual core ARM and tightly coupled Xilinx V7 fabric all on a single chip. Plus for a few hundred $$ you get a nice development board (www.zedboard.org) and a frontend wirless digital receiver FMC card - http://goo.gl/qCnJM
Not sure if that helps...