Well to be honest, i've never used one. The park flyers I build and fly need to be as light as possible so I dont use them. I'm sure someone out there would swear by them. Having had the issue you had, if you had a fuse installed prior to your melt down, chances are you would just be replacing the fuse and not the esc. I'm sure there will come a day when I wish I had installed one. Of couse the sellers of hobby products are gonna push items, they want as many sales as possible. I have never looked for one but pretty sure BPHobbies will have one if they are pushing the issue. Having said all that, it's still unclear why your esc had a melt down. So there is the slightest of possibilities that it will happen again. if the original esc was not at fault but something else caused it to melt down an inline fuse would save you having to purchase yet another esc.