I bought one of the track pumps a couple of years back.
It still works. Or at least the presta valve side does, the schraeder side gave up the ghost some time ago.
There appears to be no internal stop mechanism on mine, so if you pull up too hard/too fast, the top cap pops up and off.
Finally, the tubing seems to be a semi-rigid plastic rather than rubber and is very inflexible, making it hard to manoeuvre into position on occasion.
It's OK. I bought one as I needed one in a hurry as my previous track pump stopped working, but realistically, I wish I'd just bought a Joe Blow in the first place as I've had three now and they all added up to more than the price of a Joe Blow anyway.
The first was an SKS metal one. Thought as it's metal, it won't go wrong, but the end cap kept popping off, and the internals ended up rusting. Cost £12.99
The second I still have, but, again, only half of it works. This was from John Lewis and cost £20. The third is the £5.99 special from LIDL.
In total I've spent £38 and should have just bought a Joe Blow rather than trying to save money.
Buy cheap. Buy twice.