I really don't think the modems account for much of a difference in speed for the most part. The only thing we see in modems are stability improvements and better connectivity. They might help with signal issues but it seems a lot of that has to do with the phone and picking the correct tower.
Currently on FD24, speeds suck so bad EDGE or 1x would be better IMO. EL29, same, FD02 is the same, the list goes on and on.
Just my observations. The speeds are a network issue ie. Sprint sucks. Not the modems we use.
Epic 4G Touch (Galaxy S II) - Retired
Nexus 4 16GB - Rooted w/ unlocked bootloader
24kbps 1080p w/ 192kbps audio camera mod
by me. Also w/ How-to