Yeah, the power transfer stuff people talk about though, I’m not a physicist, but I can’t see how it’s anything other than rubbish.
Personally I use SPD for everything. Works, double sided entry, cheap, lasts indefinitely without maintenance, can walk, same shoes for road, gravel, singletrack. And of course, great power transfer!
I have both SPDs and Speedplays. And a set of full carbon soled shoes for both pedals (both Sidis). I absolutely get more out of the bike where power transfer counts (racing on the road) compared to the spds. Don’t know why as it shouldn’t make a difference. If anything, I should get less on the Speedplays as I run them with full float. Maybe it’s a perception thing. The Speedplays knock the socks off the spd-sl tho! 
And probably six dedicated pairs of socks per shoe set?
@James_T Okay - I take your point on power transfer. I would have gone with SPDs but bought shoes with the wrong hole configuration. Anyways here is what Cycling Weekly said which is kind of what I was trying to articulate:
As one of the smallest pedal platforms available, the Wahoo Speedplay Zero pedals might look alarming to some of the more powerful riders, concerned that their lollipop looks limit power transfer. On test we found that it was in fact of no concern, the cleat design provides all the strength and secure connection needed. In fact, according to Wahoo, once you factor in their lower stack height, which places your foot closer to the pedal axle, you can actually recruit more power than other set ups.
I have only done two rides but I can say personally they were much better than my Look Keo pedals.
Way more than 6 
I’ve spend a little bit over three month with the SpeedPlays now and I would consider this one of the best upgrades to my bike I made so far.
At a certain trainingload per week my left knee always gave me trouble with my old SPD-SL system. At the beginning of the switch to Wahoo’s offering, my bikefitter of choice adjusted the float of the cleats nearly to perfection. Was it just the float, or something else about the new pedals that helped? I don’t know. The next couple of weeks saw my problems slowly vanish - an effect I could never achieve with the SPDs.
It’s now my first choice for road bikes.
At the moment I’m in the process of acquiring new gear and another bike (bikes, maybe) and am wondering if my choice would also work well for my cyclocross ambitions.
Will the SpeedPlays play well in a muddier terrain?
I know, I know, it’s not the best use case and walking/running on them is still not optimal.
Let’s call my ambitions “very, very light cyclo-crossing”. 
The idea of having one system on all bikes is alluring to me. Maybe I could be fine with the drawbacks.
Has anybody any experience with this?
Maybe Wahoo will release a new generation of SYZER at some point… but this still means different systems on my bikes.
@Pierre I would be careful about cyclocross. Last week I rode a route near the beach and did get a bit of sand and gravel in one cleat. I didn’t notice it until I came home and didn’t have any issues but it they definitely aren’t designed to clear debris like an SPD pedal does.
I do like the additional float. It feels a bit more natural. Hopefully a MTB version comes out that keeps the additional float.
Definitely don’t use Speedplay for Cyclocross. Either you won’t be able to clip in. Or even worse, you won’t be able to clip out. They’re ace pedals but the cleats do need to be kept debris free and clean. They’re absolutely intended to be used for road riding. On my gravel bike, I use SPDs
I have high hopes for a Wahoo SYZR. I mean, even the naming is already spot on. 
Thanks for the input. I totally figured this would be the case. But I’m super naive and do a lot of wishful thinking.
I’m a sucker for a good cyclocross bike and use it as a road bike, commuter, gravel and light cyclocross bike. For me, it’s the holy grail.
I am considering switching pedals depending on the use case.
Maybe I’ll opt for a good eggbeater for the time being…
As previously stated, don’t go with Speedplay Zero and Gravel. As soon as it gets wet and you step in mud the fun is over.
I’m still waiting for Speedplay Powerlink but am worried my 4-hole Sidi Ergon2 won’t fit due to the low stack height I so love about them. Probably the pod will be in the way. I have to take the time to measure If there is enough clearance.
Never thought about it until I saw they have a spacer mentioned in the manual on the wahoo page.
The main advantage of Speedplay Zero especially with 4-hole specific shoes is the low stack. So adding a Spacer… 
But I hope it will fit and Sidi will bring out a new 4-hole specific shoe. Mine are already quite old and worn.
I just missed out on the last pairs of 4 hole shoes. I run the spacer on my Ergons and the stack height is definitely lower than on my Shimano cleats. Had to drop the saddle 2mm 
Does anyone know if Wahoo intends to offer the different spindle lengths anymore? I can’t find it on their website anywhere. While I can get away with the standard size and their cleat adjustability, I find I wear out the cleats faster when they aren’t “centered” on the sole of the shoe.
