Trying to decide between these two. One is HDV vs DV. I'd like true 16x9, is the GL2 going to be worse for that? What about image quality? Also expandability though lens adapaters is another issue, which one has more?

It's a bit hard to compare the two.
Like you said, one is HDV, one is SD.
As you know, in SD, the GL2 would win hands down.
The GL2 does not have a quality 16X9 mode. You can buy an anamorphic lens for it, but they are quite expensive.
The resolution on the HC1 will blow away the GL2, but not the color reproduction.
The low light is better on the GL2.
The manual controls are better.
The lens is better.
The audio controls are better.
They both have plenty of additional lenses, filters, etc that you can buy for them. The ones for the GL2 will be more expensive due to the size.

The way I look at it is:
You're comparing a prosumer SD camcorder to a consumer HDV camcorder.
Ask yourself this:
Do you want HDV or SD??
Then:
Do you want consumer or prosumer??

If you want prosumer and HDV, start looking at the FX1 or something in that price range.

Wow, I was debating this exact same thing (almost). I was debating between HC3 and GL2 and couldn't figure out eventually which one is better. Each one has its strengths looks like. I will definitely be following this thread

While I realize this is quite an old post, I am curious what model you went with?

Thanks,

Lyman