Charles,

I think there's too much wet mulch/earth around the second's leaves - that's what is happening there. Otherwise, it's a healthy plant. Secondly, you're right, probably too much water. These are Mediterranean, but dryer than the usual stuff.

The first one is more upright because it is receiving less water probably. Its growth is more compact. Both plants look healthy! Also, as the leaves get old and are replaced by new ones, they will eventually begin to dehydrate and lay flat.

I just wanted to follow up this post with some additional information. The plant above continued to decline even after I cut off the water for the last few weeks.

I was out checking it out today because it looked even worse than it had and I was tugging on the plant and it was loose in the soil. It turns out that the crown was rotting and the whole plant came free with little effort. I tugged on the other one and it was rock solid.

I started doing some research on crown rot (the crown was fetid and smelled of vinegar and rotting fruit) and saw mentioned agave snout weevil.

Low and behold when I started looking closely at the underside of the crown I found many holes that looked like tunnels in the crown from the bottom and found several very large agave snout weevils. I could hear a slurping, sucking sound which I can only assume was the weevils feeding in the crown.

Needless to say I've removed this thing from my property and am probably going to have to treat the other plant with a systemic to be on the safe side.

Another note...when I dug down into the root zone I found lightly moist but not wet earth. I do not think this plant was getting too much water. It was definitely not sitting with wet feet. The other plant looks great. Let's hope the weevils don't find it.