I currently have an Alinco DR-635T. It has been an excellent radio w/ three draw backs... there is no sub band muting, no DTMF memory, and the Digital Voice allows communications with only Alinco digital radios. I am considering the Icom IC-2820 which has at least two of the above deficiencies solved. Is the IC-2820 worth the $900 price tag (includes digital board option)? You would thing the HAM Radio manufacturers would have settled on one digital standard by now??
Do you have D-STAR activity in your area? If not, skip the digi board for now - you can always grab it later.
2820's are amazing, feature-packed, techy rigs. Cool stuff like diversity reception, GPS toys, etc. You can have a ton of fun even without the digital board.