I have 3 of the HF 4.5 with different wheels/brushes/disks on them at 9.99 when you catch them on a sale its a no brainer - if you have a big job and will be running for more than a few minutes at a time, the HF will heat up and you will burn them up whether its a 4.5 or 7 - they are descent for the $$ but if you want one to last and on big jobs that you are working them hard, well.........you get my drift, I have h/f stuff and love it for a homeowner standpoint, but when I know better and use logic/common sense you need the right tool for the job its worth it to spend the extra - some things are ok for that and its the old 80/20 rule