I just got a makita LXT impact driver from ebay. The model number is BTD140. The main reason why I bought it is that it was cheap. I just know that I will need it soon because I just bought my house and there are some projects that I have in mind. But I've never owned an impact driver before. How does this particular model compare to traditional power screwdrivers and to air tools? If you own this model, what have you used it for? Also what kind/size bits should I buy for this tool. I don't have the user's manual so any help would be great.