I definately got bigger faster with #2, it did however slow down but I did feel bigger with DD2 right until the end. My DD1 weighed 2987 grams and DD2 was 2900 grams, so not much difference in my babies weights, DD2 was actually a little bit smaller.
Oh and I thought I would add I lost weight quicker second time around too. I fit into pants one month after DD2 was born (by 2 months they were to big!) that I didn't fit into until 5 months after DD1s birth.