Now for my 2cents worth!
I have owned both radios and both are great radios but neither one did what I needed.
I like the BANKS of freq's that can be stored into the ft-7800 or ft-8800 hypermemories.So if I go from Princeton,IN to Kansas City (or princeton to daytona or princeton to durham) I retrieve that bank of freqs and put it into a hypermem to scan while I'm driving.I do use most of 1000 memorys. The software helps in doing this.
The ft-857/897 will scan in a group of twenty or two hundred.the ft-8900 has no BANKS.
here is a partial list of banks.
1 local repeaters
2 local police
3 100 mile radius repeaters
4 p'ton to dayton
5 two meter simplex