SPD (not SPD-SL) shoe recommendation?

I've got the RT5, the Velcro version of the RT4s mentioned above. Plenty comfortable enough for walking in and stiff enough for a 1400km Audax.

I got a used pair of Mavic Crossmax SL Ultimates - a deal at 110 EUR. I would recommend to hunt for a used pair if you are on a budget like me. Some guys are buying the wrong size and selling high end shoes cheaply.

Stiff, light and confortable !

Tried on a pair of Fizik X5s recently and they felt like a pair of slippers. Except for the sole of course, which seemed to be plenty stiff.

Giro empire vr90

http://www.wiggle.co.uk/giro-empire-vr90-off-road-shoe/?lang=en&curr=GBP...

 I went with Sid 5 Fit mtb shoes (in a very bright fluoro). I love them. Very comfortable, stiff enough for me (I'm not a racer, prefer 200km rides), lasting well, ratchet closure system works well, and frankly I couldn't care less whether other riders look at me oddly for using mtb pedals on a road bike - like you, I want to be able to walk un-like a duck!

Fizik M3B. Very comfortable, look lovely, durable as hell (I've used mine daily for commuting for many 1,000 km without any issues what so ever). A little on the narrow side, so make sure to try before you buy. Ok, pricey, but lovely too.

As for Ritchey pedal bearings - I managed to kill a set of Paradigm Pro pedals within 2,000km, on the road; no dirt what so ever.

Ritchey seem to use some sort of biscuit based material for the bearing races, which is a shame, because the pedals were light and nice to look at...

Perhaps not what the OP is necessarily looking for but I recently invested in a pair of Louis Garneau Platinums, very comfortable and have a very neat boa closure. I do a lot of climbing out of the saddle on my road bike and trainer and they're plenty stiff enough for me.

I'm looking at the Shimano RT4 as my next shoes, I think they look very smart. I currently have MT31 but they are over ten years old. I prefer laces because velcro eventually wears out and boas only come on shoes way out of what I'm prepared to pay for cycling shoes.

Don't overlook the Shimano xc7. Fantastic shoes that seem to be good all round (looks, stiffness, weight, comfort, etc.). Just go one size up to your normal shoes.
Bear in mind that shoe fit is very subjective, and folks will rave about what fits them and not you!

I've got Shimano RT4 - lace up, comfortable, reasonably light and great for walking.   I've had them a year and they're not showing any signs of wear (cue them falling apart on my next ride).

For quite a few years I used BG MTB sports on the road bike.  They were a wee bit stiffer than my first MTB shoes (BG Tahos) but still comfortable and walkable.  Which was a good thing when I had a mechanical and had to walk 6 miles in them :-o

I've now switched to SPD-SL and don't really think they offer much in performance compared to the SPD's just no one ever mentions mtb pedals on a road bike.  Nobody ever said anything about the BG MTB Sports as in first glance they look similar to a road shoe

Depends, how much walking are you doing in them? I have Shimano m089s which are great for walking in, I also have some Sidis which are mental stiff for an spd shoe, but not good at all for walking.

Shoes that accommodate both 2 and 3 bolt is recommended. Some might have an inner plate that you need to cut/rip out if going for 2 bolt. Keep it!

I started on 2 bolt, but as the miles increased found 3 bolt far more comfortable. More efficient, probably but on proper long rides they were a comfort revelation. 

For what it’s worth, as a summer shoe I love my Northwave Sonic 3S and my Spiuk Rodda’s are proper disco slippers, but comfy as everyone says they are. Can’t walk to the bar like a human in either though 

Oh, and I have some really expensive fi’zi:ks which are really pretty but not a patch on the other two.

I really like the Shimano RT82 shoes that I have - they look like road shoes, but fit the SPD cleats and pedals, so they can be walked in (although they're plenty stiff enough for me to ride with).

Unfortunately, it looks like Shimano has stopped making them, but now produces an RT5 model, which may perhaps work as well, although they don't have the ratchet fastening like the older model.

I've gotten on quite well with my Northwave Nirvanas. Seem fairly stiff and comfortable both road/commuting and off road too. Bonus is that they're about 50% off most places

https://www.winstanleysbikes.co.uk/product/80074/Northwave_Nirvana_Shoes_Black_Flou_Green_Euro44?gclid=CjwKCAiA5OrTBRBlEiwAXXhT6IMDGr3AieCcd90pMkjsT4bblixSmefYUCs7rCXVQFARl4hoAIZx7xoChtQQAvD_BwE

Only thing i'd mention, is if you end up using Crank Brothers pedals for whatever reason, always use the carbon sole protectors, otherwise the spring bar will go to town on the sole. 

One further point> You don't say whether you're an existing SPD-SL user or have always gone with SPDS. Reason for mentioning itis I struggle to replicate the cleat position of my sl-s on SPD shoes, so they always feel a littel far forward.