The Wright sockets fit tighter and are finished way nicer, but for home use now instead of at work, I like the slightly looser fit of the Protos because I can fit the sockets on all kinds of **** fasteners in all kinds of **** conditions. The Ko-kens are sweet. I really treated the Ko-kens more like jewelry because they are so damned nicely finished that I actually felt bad using them. Hence why I went with Proto. I don't feel bad beating on them, I already had some sets from work, and I probably wrench more on equipment than the cars so I don't need the more nuanced Williams or Ko-ken stuff. The members here that are getting those other sets from me will undoubtedly use them and enjoy them more than I would have. If I actually had the time to work on all the stuff I used to I probably would have gone a different direction when I decided to downsize and condense, but my shop is working us hard and I'm usually at work for way too long and weekends are all about playing catch-up with what I couldn't do during the weekdays. I still have some nice stuff at the house, like some Hazet stuff, but it's all 1/4" because I tend to reach for that size sets more than my 3/8".
