a2psyklnut

This will be an argument that never ends. Like the whole Shimano vs. Sram debate.

This boils down to the whole Bontrager Triangle: Cost - Weight - Quality pick two!

A hardtail can always be built up lighter than a full suspension bike. No question. However how light is too light? A race level hardtail should be in the 19.5 to 21 lb range without being "stupid" light. A race level full suspension will be in the 21.5 to 23 lb range using the same level components.

So, there is about a 2 to 3 (gross numbers) pound weight penalty keeping everything else the same.

The more expensive the components the greater the difference. If everything was the same on a Deore level bike, the difference might be $300 to $400. The difference between bikes on a Pro-level bike might be $500 to $1,000. I've seen some race hardtails cost as little as $1,200 for the frame only. Pro-level full suspension will cost you close to $1,500 and up to $2,800 depending. So, it's nearly impossible to compare the two unless you have the same manufacturer building both bikes. The reason? A top quality rear shock will cost about $250 to $400. Add to that all the bearing and privots and additional bracing/welding ...etc. and you're looking at the difference in cost.

Final question. I wouldn't want my FS to weigh the same as my HT. It's relatively easy to get a HT under 24lbs, but costly to do the same with a FS.

Which is better?

There is NO better. It all depends. It depends on the rider, the trails, the style....etc.