They really do. I just started getting up into the 115-135 lb range on my front squats. I know that doesn't sound like much (and it probably isn't), but I am doing them pretty deep. I squat down until the tops of my thighs go about 15-20 degrees below horizontal. Anyhow, I'm finding that the first night my quads are really tired, and then my glutes and hamstrings are sore for the next two days. Sore and tired legs make stance training a lot more interesting. I'm really aware of my legs for a couple of days because doing things off alignment means I have to work harder with my already tired legs. It's a good incentive to make sure I pay attention so I don't wobble and fall over.
On the plus side, I think the squats and deadlifts are finally paying dividends for my weight. I'm up to 145 lbs now. That was my original weight gain goal. I think I'll shoot for another 3-5 lbs before I start leaning down again.