My son is 26 months and I'm just starting to look into both giftedness and SPD, but IMHO my son definitely has signs of both. I have some doubts as well because of the giftedness/overexcitabilities, but he has enough of the "red flags" at http://www.spdbloggernetwork.com/red-flags/ that I hope to have him evaluated the next time I'm in the U.S. (possibly this summer). He has mostly seeking and some avoiding behaviors, which added to possible giftedness (based on my observations of his verbal/reasoning skills and memory, along with family history), has helped me understand a lot of whats been going on in my house for the last two years. The SPD foundation talks about the possibility of SPD being more common in the gifted (vs the general) population (see http://www.sinetwork.org/gifted.html).