Depends if you really want one, I have one and it is a great tablet, fast & smooth, sharp detailed screen, the tesco launcher is very bloated, but hardly anyone uses any manufacturers launcher, I personally use Nova launcher.
Have you tried doing a fresh factory re-install of your android os, it could be it has just slowed down overtime due to junk build up, some people may say just run cleaners etc, but android is so easy and quick to factory refresh, it is probably easier and more thorough.