The Time Atac design has been around for a while now and while they keep upgrading them with new materials, the basic design has stayed the same because it works. Durable, easy to engage and very good in all weather conditions, the Atac pedals are a great option for mountain bikes, commuters and touring riders who want to be able walk when off the bike. While there are many variations of the pedals including the Roc and Z-control downhill pedal, the mechanism functions the same for all of them.
Time has an Atac style pedal that will fit most budgets. The least expensive, the Aluim, happens to also one of the most durable. The pedal body is aluminum rather than a composite plastic so they stand up to getting banged off rocks and crashes better. The Time mechanism uses two spring loaded bars to capture the cleat. Like most clipless pedals, a simple heal twist will release your foot when you want dismount. By swapping the cleats from shoe to shoe you can vary the release angle but most people do best with the cleats in the standard configuration. The cleats are adjustable fore and aft but not side to side. The pedal mechanism has 5 mm of side to side float so this tends not to be a problem as your foot will find where it needs to be.
The pedal has a very open architecture which means they clear mud and snow really well. Unlike the Shimano SPD style pedals there aren't areas for mud to clog them up. The only time I've ever had a problem clipping in is after walking in wet snow that gets packed up around the cleat. A couple of kicks clears out the cleat allowing easy engagement.
In the line up of Time Atac pedals the Z-control stands apart for mountain bike and downhill use. It has the same engagement mechanism but has a much larger platform to support the foot. I like the Z-control for use on my single speed mountain bike as the foot is supported better for long climbs out of the saddle. The platform is big enough that a quick spin in regular shoes is manageable.
As all the Time Atac pedals work the same it's hard to recommend going to the high end carbon fiber / titanium options unless you are racing at a very high level. The weight savings for the more expensive models isn't a good value for the cost.
For any use where you need a clipless pedal but want to be able to walk normally when off the bike, the Time Atac pedals are the best option. Easy to use, well priced and very tough.