I never got HHD and haven't played it yet...but yeah, I don't blame you. It seems a bit boring.
I mean, if you like designing houses it sounds fun. But there's a limit on the amount of houses you can design per day if I can remember correctly and euccch. No. ..then again, designing houses is kind of boring in my opinion anyway.
There is no limit on number of houses you can design in a day. You can keep going as long as you want to.
It's great for designing every now and then when you feel more like doing that then actually playing the game. The catalogue is nice to be able to look through, and it's definitely a fun game - however I could see how one could get bored of it pretty quickly. To be honest I pick it up only about once a month probably, but I do still really like it.
Granted, house designing was my favorite part of AC, so naturally I got this (2 years after it came out, but still). Sometimes I'll go a week without playing it though, but usually not longer than that. And I usually only do like 5 villager houses a day (I still have a lot more to do).
It stinks that they no longer sell the cards though.