MTB Cleats on road shoes

I'd say the benefit of road cleats are often overstated, and would argue that comfort is more important than anything.

A good quality MTB/touring shoe will be plenty stiff enough for adequate power transfer but you'll still be able to walk easily in them. I've been time trialling for 4 years in my low-end Shimano MT40 shoes. I find the A520 single-sided SPD pedals, with their larger contact area, feel slightly better than stock M520s.

I have tried the SH-71 cleats linked on some winter boots and also have an earlier version of the RT82 shoes (mine are RT-81s).

If I were you i would buy yourself the RT-82 shoes. The SH-71 cleats are okay but feel a bit like skating on ice. My RT-81s are fairly stiff and comfy, I have done sportives in them with a A520 pedal and reckon you could race on them too.

I use SPD cleats with a pair of SPD road shoes (lighter and less chunky than an MTB shoe).

I did it because I used to walk my daughter to school (3/4 mile) before riding 10 miles to work. The shoes are pretty good; stiff and comfy, and eventually decided to put SPD's on both my bikes (old steel winter/commuter and modern carbon) so that I don't have to faff about with switching shoes around. It works for me and it certainly makes it easier to walk up a hill if you need to!

I tried these but had the same problems other users report. By all accounts they work fine with the single sided road spd pedals.

This might be what you want http://www.wiggle.co.uk/shimano-spd-road-cleats/ that said, I'd probably just stick with your MTB shoes. I only wear road shoes and cleats when I absolutely postively have to and that's to do with the fact that my road shoes are very comfortable over long distances if there was an MTB version I'd ride them.

That said those Shimano touring shoes look pretty cool too, Nick has a pair of them in their previous incarnation and he swears by 'em.

If you're racing you're not going to be using SPD cleats. If you're not, why not just stick with MTB shoes? The soles of a decent pair will be plenty stiff enough.

Walking in road shoes is a nightmare full stop - they have very little grip, and not much of a heel, as well as exposing the cleat.

The question is what do you want the shoes for? If its for racing and they need to be as light/stiff as possible, then sure go with the road shoes. But if you mean to be on and off the bike a lot (eg touring, commuting) then your mtb shoes are a better choice. Nothing wrong with riding SPDs on the road - a lot of us do.

Might be an idea to get down the shops and try some on - you don't want to be hiding an unwanted present in 6 months?

Shimano have announced a new "touring-shoe" rt82 for 2012. This has a road look but with spd cleat and rubber sole making it easier to walk around. Mavic also make a touring shoe along similar lines.
Road.cc have done a preview of the RT82 earlier in the summer.

I used to use SPD cleats and switched to SPD-SL. The SPD cleats were slightly easier to walk in as the cleat is smaller, but that said road shoes are always be a bit awkward to walk in so I usually just ride my bike instead

Not sure what you're trying to achieve. Why not just carry on wearing the MTB shoes? I would imagine that walking on metal SPD cleats without them being recessed into a rubber sole would be a nightmare.