I have the klippermate and its a solid stringer. Like the poster above said it gets to be pretty easy to adjust using the method he said. I would say that there is very little advantage to using a clutch once you get some experience on the Klippermate.
90% of your speed will come from practice and even then it will be mostly from weaving your crosses, being familiar with the process and the string pattern of the racket.
Do yourself a huge favor and do not worry about speed for 6 months but instead focus on technique and quality! Speed will only come with alot of practice. I only string my own rackets and I have had a stringer for about a year and I am at about 55 min a racket, I am not trying to break any speed records and my weaving technique is not built for speed.
I purchased the stringer to save $ and to be able to experiment with alot of different strings and tensions. Also my schedule makes it hard to get to a tennis shop during their normal hours.
Go for the Klippermate!
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