I was going to replace some old gas trimmers and the one thing I hate is getting the spool to feed properly with the bump and go trimmers. I have not done a lot of research but have seen a few road crews use the type of trimmer which uses a pre-cut line that you simply feed into the head. When I was in SEARS I saw some there and the guy said you can use ANY trimmer line in these trimmers (from a spool for example more economical) rather than buying a package of 15 pre-cut lines. Is anyone using these very much and can you truly use most any mfg.'s line and cut your own rather than the pricey prepackaged stuff? Which mfg.'s make this type of trimmer? Thanks for any help.