Spider-Man has an new suit of armour that he's had ready for a long time, and he finally gets to show it off in The Amazing Spider-Man #683. Sometime before or after those events he's in AvX #1. Regardless of how those events are chronologically linked, I've gotten the impression he's worn armour before. Why not wear it all the time?
Spider-Man has, for the bulk of his career, avoided using armor for a couple of reasons, primarily, with his powers being based in mobility and agility, coupled with a short-term precognition, it made more sense to be "light and fast" dodging damage than trying to "tank the damage" using armor.
- He depended on his short-term precognitive ability (commonly called his "spider-sense") to avoid danger. It would alert him to any attack that could conceivably harm him. Only a few of his foes possessed the ability to avoid triggering his spider-sense, Venom and Carnage being two of them.
- His acrobatic fighting style, which was self-taught, depended on his natural flexibility, agility and ability to cling to walls. With the creation of his web shooters (or natural web making abilities, depending on which universe you are in) he was able to fight in a variety of fashions creating armor from webbing when he needed it.
- He was better served by retaining his natural speed and agility in combat. While Spider-Man could take a punch by most of his rogue's gallery, he preferred to avoid damage, rather than taking it. His incredible reflex speed has served him in combat more than nearly any other fighting asset. Coupled with his strength, he is a formidable enemy in hand to hand combat.
Once Spider-Man started hanging out with the Avengers, it was decided he might need to augment his natural abilities with armors designed by Stark which gave him a wider array of options in his superhero arsenal (and to offset the loss of his spider-senses).
His latest armor incorporates the designs of the three armored suits including the Iron Spider rig, the stealth suit and the unstable molecule design incorporated into a single suit. This suit also has been upgraded to enhance his considerable physical abilities increasing his strength, speed and agility. His spider-sense had been lost and whether it will return is still unknown.
Spider-Man Armors - Iron Spider Rig (Tony Stark), Stealth Suit (Peter Parker), Future Foundation's unstable molecule suit (Reed Richards)
Spider-Man will be getting a new suit of armor starting in The Amazing Spider-Man #682. How this suit will work in relationship to his powers, and who the manufacturer is, has yet to be revealed.
The Spider Armour mark 2 didn't slow him down, nor did the Ends of the Earth or the Iron Spider. In fact, none of his armours slow him down, except for one that did in the 90's when he made this bulky silver spider armour mark 1. Since then he has improved and made the Spider Armour mark 2. That is the one with the yellow spider and black round. It is extremely light weight, compact, tight, and flexible. The reason why he dosen't use those sometimes because his skin tight costume can fit under his cloths and he didn't need it with the threats he was facing. Spiderman didn't need those costumes they just helped.