As part of the Rainmeter team I use it all the time. There is a little bit of a learning curve, but it's not really that hard. Yes grouping is something that is missing and I would very much like to see myself, unfortunately for now our developers are a limited resources and the grouping is not yet a priority. Hopefully we will get it some day. As far as learning Rainmeter here are some helpful links, and don't forget the included help file.

Rainmeter 101 | Rainmeter.net

Tips and Tricks | Rainmeter.net

Also, there is a very helpful forum if you have any questions.

Yes, rainmeter is very in depth and there are a lot of options. However, I usually just edit skins that others have already made. It's easier this way, and it's also a way of slowly learning the code. Rainmeter is just great, the possibilities are endless.

You might also want to just download some of the more popular rainmeter skins from deviantart because some of the artists actually write explanations of all of the code in the skin itself.

I have found objectdock to be fairly easy to skin. Everything is pretty self explanatory, and it all comes down to trial and error. Once you get a feel for how the borders should be set up, it's easy from there. The original objectdock skins have explanations of code in the config files, so you can quickly catch on.

I think both of these programs are easy to skin, use, and enjoy, and therefore I typically run them both at the same time.

I'm not a skinner, but I use Rainmeter all the time and find it quite easy to customize skins to my liking. But I have not created my own. Alot of people use Rainmeter and ObjectDock or DX at the same time.

As Dragonmage mentioned, you should take a look at the tutorials and cruise through the forum. Over at deviantArt, we have a Rainmeter Group where you can find skins, ideas from screenshots, addons, etc... http://rainmeter.deviantart.com/

Yes Karmat I am in the Rainmeter group for some inspiration and I have tried Rainmeter but there are some limitations I am not to happy with and the learning curve for me is very rough as I need someone to help me learn it as I go. SOrry thats how I learn (stupid ADHD). Anyway I dont' feel as though I have the support system to help me learn it as I have been to their IRC channel and they practically kicked me out cause I was having so much trouble.