Disclaimer: First, I'm not a doctor, so this is all just my opinion. You should consult a doctor before trying anything I talk about here.
Creatine monohydrate vs Creatine HCL
Second, everyone needs to know that there are 2 main forms of creatine on the market. Creatine monohydrate, and creatine hcl. I will discuss both here.
My experience with creatine was very mixed. I started out with creatine monohydrate and I simple couldn't get a solid workout since the stuff upset my stomach like crazy. Not only that, it made it so that I could barely eat anything. Definitely not what I was looking for. I know other people have had good experience with creatine monohydrate before, and there is a ton of science to back up the progress you can make with creatine monohydrate. This stuff just wasn't for me.
Creatine HCL was a bit different story. So creatine hcl is a newer type of creatine that is slightly different on a chemical level than creatine monohydrate. Creatine hcl has hydrochloride which allows it to dissolve easier in water. This means creatine hcl is more effective as it is absorbed better in the body. You also don't have to take as much creatine hcl or load. Creatine hcl is by far superior to creatine monohydrate in my opinion. Only shitty thing I noticed is that creatine hcl tastes like complete shit in its raw state.
Performance and Body Weight
So I took creatine for 30 days. My performance and body weight saw incredible gains from the creatine hcl. All of my lifts increased by about 20% for the weight I was able to do for the same amount of sets / reps just 2 weeks before starting to add creatine hcl to my diet. Also my weight increased about 5 pounds in the 1 month I was taking the creatine hcl.
I also noticed that I no longer needed to drink coffee while taking creatine hcl, which was pretty awesome. My overall energy was way higher, but it was a different kind of energy when compared to caffeine. Creatine energy gives you lots of physical energy that makes you want to lift, run, generally be a monster all the time. Caffeine I find, gives you a more focused mental energy. The creatine almost made it difficult to concentrate because I really just wanted to go lift all the time or I was a bit jittery.
Great for lifting, not great for coding/desk work.