There are two good things about playing in the Metrodome. One is it is easy to get to, the public transit has a stop right out front so you don't have to worry about driving downtown and parking. Two is the weather inside will most certainly be better than the weather outside. Unless the roof starts leaking you are sure to get the games in.
My son played in the University of Minnesota tournament there last year and will do so again in a few weeks. He enjoyed playing in a big league stadium, but little else about it. Since it is a multipurpose dome it didn't have the feel of a baseball park. The field turf looks bad and seems a bit harder then most field turf facilities. Most likely due to football and many other events being played on it. He said the ball doesn't carry well but since he is a catcher that is probably a positive for him.
From a spectator standpoint youi will soon realize that playing in a huge dome that will be essentially empty, anything you say will be heard a long way off. If you like to cheer for your own kid everyone will know who his parents are. The entrances to the stands are at the top so if you sit down low to be as close to the field as possible you will have a long downhill, and then uphill, walk. Make sure you stock up at the concession stand on the first trip.
I don't want this to come off as overly negative because after all, the only folks who will be playing ball in Minnesota this time of year will be the folks who have the opportunity to play in the Metrodome. It's just that this is an old building that has passed it's prime.