I currently have a Dyson, and previously had a Parlux. I would 100% have got a Parlux again after the old one died, but it happened right after DH got an unexpected bonus, bought himself a fancy fitness tracker, and then felt guilty and told me I had to treat myself - so I did!
My thoughts are - I really like the Dyson. The motor being the in the handle makes it feel a lot lighter to use, and I love the magnetic accessories. I also really like the heat and power settings, I find them very user friendly. It is a lot quieter than a standard hairdryer, and I really like the fact that it doesn't ever accidentally suck hair in through the inlet. It does dry my (fine but copious) hair very quickly.
However - I don't think it dries my hair noticeably quicker than the Parlux did, the Parlux was a revelation after decades of cheap hairdryers and was a massive step up. the Dyson might be a tab quicker, but there isn't a lot in it.
Because the Parlux functioned so well, when the Dyson dies, I'm not sure I would be able to justify the increased cost to replace it, and I am as disgusted by James Dyson's shoddy Post-Brexit behaviour as some PPs, which would further put me off buying another one.
I think if speed increase is your main aim, definitely try a Parlux - even buying the most expensive one, you'll still have around £200 left in your purse.