I prefer landscape slider keyboards. Ever since I was forced to choose between a crappy phone with an excellent physical keyboard and an excellent phone with no physical keyboard, I've had to put up with on screen keyboards. It's been close to 2 years and I still cannot type as well on a touchscreen keyboard as I did on a landscape slider keyboard.
I've tried a number of touch screen keyboards. Here is my assessment of each:
Kii Keyboard -- This is the one I currently use most of the time. This keyboard has my personal favourite because it has the landscape layout that I like the most. I am able to type with the fewest errors with this layout compared to any other layout of any other keyboard I have used. It also has a Canadian English language. The significance for me is that the spelling is like UK English and it has the dollar sign. The auto-correct is average. It is easy to add new words to the dictionary and to blacklist some words as well. It also has a number of other features such as layouts with number keys and gesture typing.
Swype -- This is the secondary one I use, only in portrait. Swype is the best gesture typing keyboard I have used. It is a step better than any other keyboard I have used. Gesture typing makes it easy for me to type while using the phone with only one hand. Some people like gesture typing and use it regularly.
SwiftKey -- This keyboard has the best auto-correct/text prediction of any keyboard I have used. It is very good at predicting your next word. It analyses your typing style and learns from it.
Thumb Keyboard -- This keyboard has a lot of different keyboard layouts. I used this when I first got a keyboardless phone.
MessagEase -- This is a non-standard keyboard with a non-standard layout. Typing with this keyboard requires both taps and swipes to type each letter or symbol. Of all keyboards I have tried, I have made the fewest errors with this keyboard and by a significant margin. The reason I don't use this is the huge learning curve required to become proficient enough to type at a reasonable speed compared to other more traditional keyboards. If you are new to typing on a touch screen and haven't become proficient with traditional keyboard, perhaps you should give this one a try. Be warned, that there is a significant learning curve.
My advice is to try a number of keyboards. I would suggest you try both Swype and SwiftKey. These are amongst the most popular alternate keyboards used on Android phones. Swype has a great gesture typing feature and SwiftKey corrects your errors and predicts your typing the best. Try others if you don't like them.
When I was using physical keyboard, I never used auto-correct. My typing was accurate enough to not need it. When I switched to a touch screen keyboard, I struggled for months trying to type. I didn't use auto-correct as I wanted to learn to type accurately. After 6 months, I gave in and activated auto-correct. I felt that there was no way to type without making massive numbers of keying errors without any type of tactile feedback from a physical key. The keys were just too small.
Only with MessagEase could I type without auto-correct, because the keys were huge. There were only 16 and required either a tap or a swype to type a character. MessagEase was really slow to use and required a significant amount of practice. If you feel up to it, then give it a try.