This topic keeps coming up, and the arguments are mostly all the same each time. Use what works for you I think is the best advice, but personally I like my SPD setup. I rode with regular pedals and straps ("rat traps") for a very long time before finally trying out SPD pedals and shoes, and now I wish I had changed a long time ago. Being clipped in makes sure my foot is properly positioned on the pedal, and clipping into the SPD pedals is much easier than it ever was with the straps (my Shimano pedals are 2-sided which is a big factor here). Getting out is also easier IMO, once I established the right muscle memory, but even in panic situations my clips are set loose enough that I can pull out if absolutely necessary (I use position
#3 ). For the people complaining about "clicking" when walking, I found that depends on the shoe. I used to have some inexpensive Shimano shoes, and they did indeed click when walking on hard surfaces, but I now have some Gyro shoes (black with orange laces, I forget the name) that are quite comfortable to walk in and manage to avoid the clicking sound.
I like the recommendation for the Shimano XM9 SPD hiking boots; I'll have to think about those, though at $250 it's an investment. I thought my Oboz boots were expensive...
And I agree with the post about road vs MTB pedals and shoes: I don't see any advantage at all to road shoes, except possibly a tiny amount of weight that would be significant to a professional racer but not me since I value walkability more.