I was looking at this site and wondered which is best in use, the flat bottomed sort or the kind on runners.

Any pros or cons for either?

http://www.sledges.co.uk/Home/tabid/94/Default.aspx

Police riot shield 😉

"Police riot shield"

It's PC's gone mad!

I suspect flat surfaces work better because despite the old "in my day the fastest sledges were steel railed ones" that I've been told a few times. But then why do DH skiers use narrow long skis? Ultimately its going to depend on the snow, in soft snow you need enough area to support weight without sinking, but too much frontal width (ooh err) creates drag, so that's your compromise. On hard packed snow, narrow=better.

And thats only if you consider fast as best, if you toss control and comfort into the matter you're opening up a world of possibilitiues.

Depends on the snow!!!

Dunno, but…. "sled".

Wooden frame with narrow & waxed steel runners.

as above, depends on the snow. On deep snow the narrow style ones just sink where the flat bottomed ones float over.

we used an inflatable dinghy to very good effect on the Downs in January.

Take the bonnet of one Mini (old style).
Polish vigorously with a tablespoon of T-Cut.
Buff to a high luster using a small knob of Turtle Wax and a soft cloth.
Garnish with a slight misting of Back to Black or similar silicon-based car interior sprays.
This isn't just any sledge, this is the fastest f*****g sledge I ever rode on.

Sled = american and generally used for heavy-weight transport duties. But 200+ years of usage might allow a little movement in the UK word choice.

Flat, but with runners. Covers all eventualities. Sadly our two sledges were used to the point of destruction over Christmas and January. 🙁

One with runners, preferably from the 1970s. My Dad turned up with my old one just before Christmas, unused since 1977 and it was a good deal quicker than all of the plastic tat. Also you can get at least 3 folk on it. That's the thing with welded steel and wood.

To be fair he has another one in the shed that he doesn't want if anyone needs one – he'll be pleased to be rid. e mail in profile.

Inflatables are great, but anything without some kind of "keel" is highly likely to spin around as you're going down – which can be great fun. Our inflatable invariably ended up backwards as most of my weight was at the back.
From my experience, traditional toboggan-type ones aren't much good. Maybe it's cos I'm heavy, but they just seem to sink in. Whatever spreads your weight over the largest area, I guess! If I'd had a free choice, it'd be the dustbin lid style ones…

We have a very traditional Davos sledge, it's over 25 years old and can hold two people at speed. Anything plastic is shite.. 😉 It goes miles further than the rest 8)

My dad made a timber one for us kids years ago. I improved it by putting plastic curtain rails on the bottom

On piste, something like the Davos.
In powder, plastic.