In reply to puppythedog:
Alpkit Gamma or Manta will be great for Scottish winter. Good bright main beam and the lower brightness LEDs are fine for walking in/out with. Manta has less bulk around the back of the helmet but loses the rear red LED of the Gamma (great for cycling or for seeing where the kids have got to).
Petzl Myo RXP is a good torch. You can buy 3.5 Alpkit torches for the same price.
The Nao looks really good but I've seen it dim right down in snow because of all the reflections. You can bypass the intelligent mode and set a constant illumination. The self adjusting-ness is really very clever and quite intuitive, you wonder how you manage without. However for plodding along in typical winter conditions they are probably overkill. You can by 7 alpkit torches for the price of a Nao.
The Cree based "many many lumens" headtorches available on eBay or Amazon are amazingly bright and great for moving fast. They might come with a separate battery pack for sticking down yer pants to keep the batteries warm and eking out that last bit of charge - you may need it as these torches tend to be quite thirsty!
On the recommendation of a previous what headtorch thread on UKC, I purchased a Princeton Tec Apex which I've owned and used extensively for 3 years. Comes in at about 7 Aplkits. I like it.
* 4 x AA batteries for a long burn time and easy replacement (no unreplaceable internal rechargeables here)
* 2 level super bright main beam (good for fell running)
* 2 level wide angle side LEDs (perfect for walking/map reading/DIY/etc)
* Head top strap for stability (needs it as it is a little on the heavy side)
* Very comfortable to wear for long periods
* Waterproof (good for occasional caving expeditions)
* Big buttons are easy to use even with thick gloves on
* If you are inclined there are several "mods" you can do to add a better LED / reflector to boost the output of the main beam
* Haven't had need of the customer services but I understand that is OK but not stellar.
edit: also, to echo Martin's post above, a backup torch is invaluable. I've got a Petzl E-Lite which weighs nothing but has enough juice to get you off the hill.
edit edit: some of the sentences ended up mixed up
Post edited at 08:48