LIke others have said , once you go clipless you wont go back and I agree with one who says mountain bike shoes are much easier to walk on.
i think we have the same bike as I have just noticed your avatar!!!! cool
I went clipless on my hybrid and have just changed the pedals to my new dolce its is brill and i love it xxx
i also did a cycle aong the River Nile and took my pedals with me to go on the bike I used there as I felt i could not do without them,
I have mountain bike shoes by specialized and they really helped with not having numb or tingling toes too.
I have to say I fell off a couple of times when I first clipped in as i wanted to see if i could unclip in an emergency (I coudnt) so i had to practice and then realised you can have the spd pedals a bit looser to let you out easier.
i do recommend unclipping one side as you approach a junction just to be ready until you get used to them
sorry if you already know all this but I would have loved some help and advice when I first used them but I did not have access to this brill forum

good luck and just go for it

Scarlet x