Depends on what you want your roller/trainer to do. Rollers are good for learning balance and smoothing out your spin technique, but they do not have anywhere near the resistence for strength improvement as the trainer has.

For about 6 months I read and asked questions in 3 different forums about rollers and trainers and the type recommended the most was the trainer; and the trainer recommended the most was the Cyclops Fluid 2. The Fluid 2 is about $100 less than the Kurt Kenetic; and for even the best of riders your not going to max out the wattage rating of 750. Lance Armstrong's sustained power output for 1 hour is 450 watts, so do you think you can do more? Of course not, and Kurt Kenetic advertises 2,500 watts? Your never going to get close to that!! Don't get me wrong, I think the Kurt Kenetic is a excellent machine but it's an overkill. The Cyclops Fluid 2 is more in line with real world wattage output of even the elite cyclist. All Cyclops come with a lifetime warranty as well, so there's nothing to worry about.

I bought the Cyclops Fluid 2 after testing Cyclops cheaper little brothers ( and another brand with the side rim type), and found the Wind and the Magnetic just did not have that natural road feel, and the Wind was very loud; plus neither would go higher than 250 watts. But the other two, the Cyclops Magneto and the Fluid 2 were very smooth with a road feel to them; both were very quiet; but the Magneto max wattage was 450 while the Fluid 2 was 750. So I opted for the Fluid 2 so that I would always know that I have room to grow. BUT, if you don't want to spend more than $175 or so, the Magneto is the best buy.