I bought a cheap unbranded Chinese one, followed by the Parkside PHP 500 B2.
The first didn't last five minutes before the stick-pushing mechanism broke - just plastic, not surprising.
I was disappointed by the Parkside one, as I've always found their tools to be good, for non-industrial use at least.
I soon got fed up with the waste of glue which continues oozing out for a while after the trigger is released. You can't do anything neat.
Don't ask me how to change sticks once the one being used is past halfway. I used the second one (different colour, fyi) to push the first all the way through, basically wasting the remainder of the first.
The pushing mechanism broke after not much use, so that's another one down the drain. I don't know, but it sounded and felt as plastic as the rest of it.
That mechanism has to take a lot of use, and abuse as it's warming up and you want to see if it's usable yet, so making that the weakest plastic link verges on cowboy manufacturing, imho.
I'll have a look at those recomnended above, with my pocket in mind.
Sigh! Does anyone else think it might not be worth bothering at all?