Yes, the title says it all! This was exactly my reaction when I played an MXR Dyna Comp for the first time. If you're like me and you love funk/ funk rock, this is the pedal you will need! Although the basics of funk are in your right hand, but everyone likes good add-ons to enhance their sound!
Sound: Unlike other pedals, a compressor won't alter your sound or cause audible difference initially. It has more to do with compressing the dynamic range of your signal to create a tight, punchy groove (in funk). But it can be used to boost guitar solos while playing live too. It takes time to understand the compressor, but once you get it, you'll love it! Some artists like Nile Rodgers have actually showed up to gigs with JUST a compressor pedal and a strat, then plugged straight into the DI!!!
Durability: Will withstand minor abuse. Built is good and foot-switch works with just a tap.
Overall: You may/may not find it useful. So try it out somewhere before buying. The two knob compressor from MXR works best for me with guitars! I get confused with the multi knob Boss compressors (but that's just me).
PS - Hissing sound with high compression is normal. The pedal is not defective. You just have to learn to use it in the most optimum manner!