Does half an hour count?

Last night I took Louie out, after Sadie so I was expecting some excitement as we walked the same path, but I got at least half an hour of walking by my side and not ragging my arm out of it's socket. Not got the focus there yet but I think he is getting it.

I am using the stop and turn when he pulls method, for 3 months now, so am I doing it right or should I be getting quicker results?

If you do that every day for 6 months... you should be getting there.
Different dogs progress at different rates.
I still occasionally have to practice this with Daisy for a few minutes to calm her down if she`s really keen.

Well up until recently my OH has been walking the dogs altogether and I don't go with him as we tend to argue when out walking - I'm just too picky over what he does and I know I shouldn't do it but I do and thats just me.. and I will take Louie out separately on occasion, but me and the OH have worked out that the dogs can go for a together walk in the morning and then Louie will have a separate walk in the day and at night. So hopefully results should be getting better.

He still pulls when he sees another dog, although he met an irish wolfhound last night and he wasn't too keen on her size - but he still greeted her then walked with me away from her.

Then the dreaded 4 legged felines came out to play and I had to cross the road to stop him sniffing it out and dragging me.

I know I still have a lot of work and I am working hard with him but I will get there.

Thanks for the support Claire. glad to know I'm doing something right.

I personally really like to turn around when they pull method. I also use the "go around random objects and keep them guessing" method. I like to keep them guessing by going round bins, benches, trees, anything I can. I also randomly stop and change direction of my own accord, not just when they pull. I know it looks weird to an outsider, but it can really work if you're consistant.
Sounds like you're getting there and there shouldn't be a time limit. If he'd got NOWHERE by now, maybe you'd need to look at a different method, but you have made improvements, so keep going