Substantial feeling SPD pedals?

You an't adjust float. I have normal XT pedals and Trail versions - trail are better if you need to have your foot unclipped as you can still pedal/balance on the platform. You'll get used to the float and not notice it after a while.

Platforms that provide extra support will also interfere with clipping in and out. Persevere for the moment and see how you get on (shoes with particularly soft soles might always feel a bit crap if they bend too much around the cleat)

I like a small platform of some sort and usually use Crank Bros Candy's. If you want a bigger platform still then the CB Mallet E pedals might help.

Get some crank brothers mallet e pedals, I've just got a pair of these with Endura MT500 shoes, zero issues clipping out and when you're clipped in they feel like platform pedals, they're excellent.

The soles actually feel pretty stiff considering I bought the shoes dirt cheap 2nd hand (didn't want to drop a load on something I might hate!) - I can't actually feel the pedals under my feet I think it's just the float that's putting me off at the minute.

Those Mallet E pedals look ideal though.

Time mx6

The crankbrothers do come in a nice box though.

I've never used Shimano pedals but thought lack of float was a thing with them? Do they just need a bit more spring tension?

How old are your cleats and how much tension have you got in the pedals? On most Shimano pedals you can turn the tension up for release and I find that can give you a slightly more secure feeling.

On platform style spds I like my Nukeproof Horizons (the bigger / squarer version). I use them with Shimano AM7 shoes and they’re great.

I think the platform with pins style pedal doesn’t play nicely with xc style shoes with chunky outsoles - you need a more flat style spd shoe.

Time mx6

These look cool and half the price of CB Mallet E, off to check out some reviews!

Mallet e/DH and some flexible shoes is the answer. The Shimano trail pedals don't provide any additional support when clipped in and neither do stiff soled shoes.

i moved 4 bikes over from crankbrothers to time some years ago. they're very similar systems however the CB rotates around the axle independent of the pedal body which means you require an additional seal at each end of the spring mechanism. the time system uses springs which are completely separated from the axle so no additional seals required. i never noticed any advantage of the CB system in terms of clipping in or out. i have never serviced my time pedals. ever. the CBs required regular care once those seals at the end of the springs failed and they were never part of the service kit. i also snapped an axle on a pair of candies (stainless) and had a mallet pedal detach itself from the axle on another ride.

the CB's marketing department is far superior to the time one though. 😉

I never got on with spds with platforms at all. Hard to clip in and still rubbish to pedal when not clipped. Decently stiff soles mean no pressure points / hotspots

Shimano pedals are the only shimano components on any of my bikes they are indestructible and just work

I swear by Nukeproof Horizons for a platform and a standard spd interface. Pins like a chunky flat pedal and clips.

XT trails don’t have the same level of grip on the platform IME.

Easy to service too.

I got these after wearing out shimano pedals and finding other ones too slippy in my conditions.

I've got time MX on anything that i use where i might be clipped out for any reason. And some of the old aluminium DH pedals for the winter bike, for when things freeze up.

Decently stiff soles mean no pressure points / hotspots

I don't feel like I have any pressure points with the AM5 shoes, I think it's more the float that I'm not liking the feeling of. Was thinking if there's a bit of a grippy platform for the sole surrounding the cleat to grab onto then the floaty "ice cube" feeling might be reduced?

I may be overthinking it a bit though, will persevere with what I have for now and wait til I get it on a proper trail to see how it feels.

All I can think is that you have the spring tension wound out completely and that the cleats are very worn.

The cleats are brand new but the pedals are pretty old so that might not be helping. I've got the release pretty tight but it doesn't seem to change the feel of the side to side motion anyway.

Time for sure. Mine normally last more than a decade without any servicing. They are brilliant for float and engagment.

And they're cheap.

I tried Crank Bros once. Utter crap by contrast.

Just persevere with the Shimano pedals, float is a good thing. You'll soon learn the distinction between the ice cube and not clipped in - trust me!

I have the same thing in reverse, the "in one position" element of flats is very alien to me, and gives me knee pain before long.

Just an update, I finally got round to having a proper ride on the Shimano pedals and you guys were right, I didn't even notice the movement on a proper trail. I'm loving it, wish I'd tried it years ago. It's given me the confidence back on a hardtail as I'm not worried about my feet being bounced off, and they're always in the right position so one less thing to think about.
Pedalling feels more efficient and no sore feet from soft soles. No issues jumping or any unwanted unclips (yet). All round a great move. I may still try those Time pedals in the future but will run these til they start having issues.