I use 80 metres microbore on a petal reel - the bright yellow ebay stuff. I use hot (well, very warm) water and the hose is rated to 80°c and I've not seen it bulge yet. I step that down via a rectus fitting with golf ball style protector to gardiners green pole hose, then via a push fit to the length of similar pole hose permanently attached to the pole.
Pros? Nice and light to work with. Gardiners green has lasted 4 years and only signs of wear are through abrasion and snags. It's very supple when warm and lays flat. The connections last a couple of years too. In fact I've not replaced the push fit in that time.
Cons? When cold both sets of hose tangle for fun, leaving quite the trip hazard for myself, customers and the great unwashed. The green pu hose LOVES to snag around car tyres and wheely bins, seemingly just to spite you.
The petal hose reel has taken a battering and has lost it's powder coating within the first 4 months but is still going. The next one will be fixed in the van with a diy electric reel conversion. Until then the reel/hose set up has worked really well for me but I'm always up for any improvements.