I am using Kobo Libra 2 for reading books.

If you are just planning to read books, I suggest you get a feel of the smaller one - Clara 2E. The Libra2 can be a little too big and heavy to bring around. If you're planning to read manga, the Clara 2E is a little too small.

Tabs have their own benefits, like being able to read colourful pdf documents and you can even borrow magazines from National Library to read on tabs.

Do note that e-book readers are usually using much slower processor, so there is noticeable lag compared to tabs.