I buy a lot from US and used both surface and airmail. Surface is indeed slow, and from my point of view, it's not worth. I rather pay a little bit more and have the box in a week than save some money and keep wondering for two months where my box should be now.
Regarding the taxes, it doesn't matter wether it's a gift or not. I've only paid taxes once -for a seat- because the seller insured the box, and declared a total price of the seat and postage combined. He did it with good intention, so in case the box was lost I could recover my money. The tax people at the spanish airport saw a big box, with insured content, for a value of 120 bucks and decided it had to pay taxes.
Another day I had to go and pick up a box myself because the seller didn't fill out the custom's form. So I had to take with me the eBay printout to proof the value. The clerk told me that legally EVERY packet coming from a non-EU country is subject to taxes, but it's unpractical to stop every one. I read between the lines the they only stop the expensive ones, as well as the ones coming from Asia with expensive electronics, where the buyers try to save some money buying abroad.
When I showed the eBay invoice (55 bucks) the lady told me that for that amount it was not worth the effort, and I agreed. I only had to pay a couple euros for the handling. She told me that, in Spain, everything under 50 euro -shipping included- is tax-free. So, when I buy something more expensive, I ask the seller to specify a lower value, and if possible, to specify "used parts". That way it's clear why the price is so low.
Raul