Riding rigid will teach you technique.You will have to ride the bike, and not just hit things and let the bike and speed do the work. Get the technique and those uphill climbs are a doddle after losing two or three lbs at the front end. Lifting that front wheel over a gnarly root is a lot easier, and on the flat, that bike that feels like 20lbs will ride like a 20lb bike. Only problem you may find is downhill, where if you are tight, your shoulders and forearms will die on you. Someone has mentionedit, but don't get a death grip on the bars, but do keep the forearms tight to counter any big lumps that may try and throw you off line. I only succumbed to Suspension forks two years ago, but I only have 80mm forks set as hard as possible. just enough to take the sting out of the trail.