I ride Time ATACs. I have three different models on three bikes: the Aliums, the ROC Carbon, and the newer XC. The first two have the old round section springs, while the last has the rectangular section springs.

There's no difference whatsoever between these pedals apart from the weight. I wouldn't be able to tell them apart without looking down. There are comments on the internet about the rectangular section springs wearing faster, but I have not personally experienced this.

I quite like these pedals. They have never unclipped unintentionally and never jammed due to mud. They clip in positively with a click, and unclip easily. The cleats have two release angles depending on which cleat you put on which shoe. I use the harder to release setting. There is plenty of float in the pedals. This is not the soap-bar type of float you get on Speedplay pedals. There is some friction when you rotate through the range of the float, but within this range there is no spring centering. Once you reach the edge of the float range, you begin to feel the spring, and pushing further, you clip out.

After years of use, my pedals are all still going ok. They have dustcaps which you can unscrew to access the bearings for service, though I have never done so. The left pedal in my XC set has developed some play and will require service soon. These are about four years old and are my newest pair. The other two pairs are solid. I'm not sure if this is coincidence or due to the newer bearing design being weaker.

I replace my cleats at the same time as my shoes. As the sole wears, the cleat becomes exposed and wears with the sole. Once the sole is sufficiently worn, a new cleat would protrude significantly and wear quickly when walking. I don't know if Shimano steel cleats can take this kind of abuse, but the Time brass cleats wear immediately if you walk on them. That said, I have never had to replace cleats before wearing out a pair of soles.

Edit: I just went over to my bikes to look at the pedals. The Aliums, despite being years older, are definitely doing better at the bearings. I'd stick to this proven and cheap model and be done with it.

Edit 2: I went to the Time site and it looks like they are no longer selling the Aliums. Oh well.