Mixer front-end receivers are now seen mostly at more than 40 GHz where LNAs are still expensive.
Matching mixer IF output to a IF LNA is easy via 50-Ohm short line as both devices can be optimized before joining.
When designing mixers I have not used anything different from 50-Ohm IF, with very good results in all projects.
One of my 35 GHz designs, a mixer plus an IF LNA, featured 2.7 dB DSB noise figure (really measured). It is better than a MMIC LNA receiver, and lower-cost.