They usually X-ray bags these days. I haven't had them search bags by hand for awhile, going through the 'nothing to declare' line, although they are likely to pull aside some Brazilians coming home who they suspect have gone shopping. You are allowed (iirc) to bring in $500 worth of stuff. I would take the iPad out of the box and perhaps put some sort of personalized wallpaper on the screen to show it was used and for personal use. I would not suggest bringing multiples of any electronics; this indicates 'for sale', not 'gift'. If they decide to tax anything, it would help if you had the original receipt to prove value; otherwise they can pretty much value it at whatever they think it's worth (top value, not discounted or sale price) for tax purposes (and the tax to be paid would be close/equal to the value placed). Depends on how comfortable you are with financial risk I guess.