I live in Northern NJ and last year I had my property graded and some backfill added, afterwards I seeded. The lawn came in thin and was very soft and when you walked on it you would "sink". I asked my buddy who did the same thing a few years ago and he said that it was normal and it takes a long time for the lawn to "harden to normal". I plan on overseeding the lawn this spring but I was wondering if a lawn roller would "harden" the soft, muddy, sinking lawn. Would I roll the lawn before or after I seed? I also saw a "powerseeder" online, would I be able to use this with a thin established lawn? Would I get better results than using a spreder to seed? Please give me some advice on what and when to do each. Thanks.