Paul if you can pay that bit extra go for an Iwata Eclise HPBS.
I have tried 2 H & S brushes. I also have 3 Iwata two of which are supposedly better or bluntly more expensive than the HPBS.
The HPBS is a revelation. First it is small ie not as long as your average brush. It can get into smaller spaces. After 3 years with H & S then 3 Iwata the HPBS is now the only one I use for all work as it is such a delight to work with. Ocassionally in weathering I have gone back to the more expensive one with smaller needle/nozzle only to resort back to the HPBS.
The finish is superb much better than the H and S brushes. The most close brush that I have tried is the HP CS and in comparison to the HP BS it is a monster to handle.
The HPBS has a small cup the larger cups on the average Iwata stick up high in visions way especially on close work. It also allows access into intricate corners etc.. Not to worry about the smaller cup there will be few occasions you would run out of paint in model making. If so it is so easy to top up.
For general paint coverage for large paint jobs it is perfect. For weathering it is equally good. You can get down to much less than an inch with great control over the paint flow.
It has a .35 needle/nozzle (an optional extra is a .5) which is perfect for model making and medium heavy paints ie acrylics Vallejo Lifecolor etc.
http://www.scalemodelshop.co.uk/iwata-eclipse-bs-airbrush-iw-ecl-bs.html
Laurie