I am in the market for a backpack sprayer. I have been looking at the Solo 425 (Bailey's- $74.95), Solo 425 Deluxe (Forestry Suppliers- $96.95), and the new Stihl SG 20 (any local dealer in Cincinnati $99.95). I have a twenty acre woodlot that I am clearing of bush honeysuckle, multi floral rose, ect. The primary herbicide that I will be using is glyphosphate. Any recommendations, tips, pearls-of-wisdom, would be greatly appreciated.