I'm all about the sim games, and have spent much of the last 6-7 years simming thru seasons of games to get to the offseason activities. I even like NFL Head Coach, which some people find boring. This game, however, is just too boring to build a franchise. I'll say it again, its too boring to build a franchise. I could definitely see the fun in trying to maintain or improve a good team. But the favorite thing for sports gaming fans everywhere is to turn a doormat into a powerhouse. The time and effort it would take to build a franchise simply wasn't worth it to me.
The tedious part is they want you to monitor and set the lineups of your minor league teams. You have access to your entire farm system like never before, easily sending players up/down the baseball ladder. This becomes important, because in my years I simmed I couldn't buy a team...there were few good free agents available...and those guys were grossly overpriced. Your young talent is mostly bums (like real life), meaning much of the time you put in with your farm system is all wasted.
So, in short, you are expected to keep up with 5 different franchises at once. If you can do this, regularly, day after day, hour after hour...I have zero doubt the satisfaction you'll feel for building a winning team has to be one of the best in sports gaming. For me, it wasn't worth the investment in time.