It really depends… But
The hierarchy of decisions has to be the following. If you want to build an SBI site, you should have access to a …
1. PC or Notebook/Laptop (inc. Mac) for building/maintaining your site.
2. (Optional) If you already have a PC/Mac, and want to be portable while building/maintaining your site… buy a notebook or netbook with a slightly larger screen (ie. 11"+ is good).
3. If you don’t care to be portable, and already have #1 then buy a tablet for reading/researching/emailing but don’t expect to be able to manage your site properly (see note below).
4. If you have #1 and #2 already, then a tablet is great for reading/researching/emailing but not much more.
Don’t buy a tablet and expect to build/maintain your website, unless you can plugin a keyboard & it runs Windows or a decent OS (not iOS). iOS currently lets you do many things in SBI’s system, but you cannot edit an HTML page or a BB-page properly at all, and scrolling seems to be a problem. There *may* be workarounds, but they will not be very effective unless you REALLY know what you are doing.