What did you think? 你觉得呢 vs 你觉得啥
No they don't mean the same thing.

你觉得呢？

This translates to "What do you think? (about the topic we just talked about)"

你觉得啥？

This does not sound natural. It can mean "What did you just say (about your opinion / feeling)?" but its not common usage.

你觉得怎么样?

This is almost the same as 你觉得呢？, but is slightly more polite. They are equally appropriate for spoken, written, and texting.

Or, in certain context, this can mean "Are you Ok? do you feel sick?".