I don't know the difference between the 77 and 78, but here is my 77. Genuine Fluke leads are more flexible than the less expensive(Chinese) ones. I also use a clip on the end of the probe sometimes and again the fluke ones are better than a set I tried from RadioShack. I hold the manual, clips,leads and a jumper wire in a large Altoids tin so everything stays together and undamaged in my toolbox. I would go with a used Fluke over a new Chinese meter. I justify good tools by there is a job to get done and you need them to work or you end up paying someone else to do it. For less than one hour what a shop would charge to figure out an electrical problem you can get a used Fluke that you will pass onto your kids someday. I have used my fluke on 110v, I would not trust my life with a Chinese meter.