How do I select the right SDR platform for a given application in terms of bandwidth and dynamic range?

Selecting the right SDR platform requires matching the platform's key specifications to the application requirements across several dimensions: frequency range (what RF frequencies must be covered, from HF at 3 MHz to mmW at 6+ GHz), instantaneous bandwidth (how wide a spectrum segment must be digitized simultaneously, from 200 kHz for narrowband communications to 400+ MHz for wideband applications), dynamic range (determined by ADC resolution and spurious performance; 12-bit ADCs provide approximately 72 dB SNR, 14-bit approximately 84 dB, 16-bit approximately 96 dB SFDR), processing capability (FPGA size and processor speed for real-time signal processing), interface bandwidth (USB 3.0 limits streaming to approximately 200 MSa/s, 10 GbE supports 1+ GSa/s, PCIe supports multi-GSa/s), and cost (ranging from $25 for RTL-SDR dongles to $50,000+ for high-end platforms). Popular SDR platforms span a wide capability range: RTL-SDR ($25, 8-bit, 2.4 MSa/s, 24-1766 MHz, receive only), Airspy HF+ ($200, 18-bit effective, 36 kHz-260 MHz), Ettus USRP B210 ($1,500, 12-bit, 56 MHz BW, 70 MHz-6 GHz, TX/RX), Ettus USRP X310 ($5,000-8,000, 14-bit, 160 MHz BW, DC-6 GHz with daughterboards), and Keysight M9703B ($30,000+, 12-bit, 8-channel, 2 GSa/s, for high-end measurement applications).