What exactly do you want to do on the new machine? Tablets are great for browsing the internet, emails and social media but not so good for typing long documents. Storage is limited, too. I use my smart phone more than my tablet.
If you need a proper keyboard look at a Chromebook. These have their limitations, too, because there is practically no storage on the machine itself - it is all done in the cloud, so if you have no internet access it is unusable.
Netbooks do have a hard drive but very little RAM, usually 1 or 2GB, which can make them slow and clunky to use. Both netbooks and Chromebooks should have long battery lives, which is important if you use it on the move a lot.
I love my smartphone.