I have two Scorpion exo700's and they're the quietest helmets I've owned, which includes Shoei and an Arai Astral. I tried the '1000 but didn't like it and didn't need the whole inflatable cheek pad gimmick thingamawhosit. I will never own an Arai again as it was, as far as I'm concerned, the poorest quality helmet I've onwned. The top vents would not stay fixed (replaced them numerous times) and same for the shield vents. The rubber strip around the bottom also started to just 'fall off'. On the other hand, I had it painted like an eyeball and it's damn cool looking.
The problems you had with your Arai may stem from having it painted, if the vents and gaskets were removed for paint. Regardless, I'd call Arai America and see if they won't do something for you - their customer service is outstanding. I've had 0 complaints about the build quality of my helmet, and neither have most Arai owners I know.
My main helmet is an Astral-X too, but I'm looking to replace it this season for a few reasons: I don't like the visor change system on Arais, and the visor on mine fogs up like nobody's business in cool, damp weather. It also got smacked around when I was rear-ended last year; x-rays said it was sound, but I don't really trust it. Besides, it's scratched all to hell now anyway.
I ordered a
Caberg Trip from the UK a couple of months ago. Overall I liked it, but it was very much the wrong shape for my head and I wound up selling it on another forum. Unfortunately getting the right fit has been a continuing problem for me - I have a "long oval" shaped head and most helmets put a lot of pressure on my forehead. I've gone through various models of HJC, OGK, Scorpion, and now the Caberg, and the only helmets I've found so far that fit comfortably are the Arai mid-oval and long-oval helmets (Astral-X/Vector, Profile, and the off-road XD).
I've got my eye on the
Vemar Jiano now. It's a flip-up that Vemar describes as having a mid-oval fit with extra room front-to-back and a slimmer fit side-to-side. With the Caberg I found I really liked the convenience of the flip-up, and the Jiano is DOT and ECE 22.05 rated as a full-face helmet, so I'm less concerned about the chin bar/flip mechanism giving out in an accident. If the Jiano doesn't pan out - I'll have to mail order it and pray it fits better than the Caberg did - I'll probably wind up buying either a Shark RSX/RSI depending on fit, or another Arai.
Regarding noise vs. ventilation, I'll take a noisier helmet with better ventilation every time. I don't really notice helmet noise much because the earplugs I always wear bring it down to background levels, and I'd rather not stew in my own juices when I'm out in hot weather.