First off, it's $3 so why not give it a shot, and it's NOT an EA extra. I play exclusively offline and — unless I've missed something (entirely possible) — find it ....challenging... to own a game that was created so that it could only be fixed (patches/tuners) or accented with extras via online, and with the latter, for EA costs (heck, I may be wrong here, too).
SEcondly, (sorry for that rant), by gaining a spreadsheet with all attributes rated numerically for all recruits, you'll be able to recruit for
your system and style of play. Play mostly zone D? You'll be able to distinguish b/t LBs and DBs with the same OVRs but with different Man/Zone/Press coverage ratings. (Note that you can't see the Press ratings for ATH-DBs in the EA menus, if you play more Man/Press like me you'll gain that info w/ Pocketscout). You'll become less dependent on OVR, picking recruits based on the characteristics you want them to have for your style.
Third, the all-POS ratings provided help you with potential change-POS's guys. I regularly move LBs to DE, SSs to LB. Twice in past four '11 recruiting seasons I picked up QBs with Avg to below-Avg OVRs but with stellar HB characteristics. One's a Jr starter and I've RS'd the other. MUCH more difficult to foresee these changes w/o Pocketscout using just the EA recruiting grades.
I'm like the poster several before, I am so reliant on the program I don't know if I'd be able to recruit any other way.