Is 2 better than 1? YES, yes, yes!
We got our second about 6 weeks ago and it's really the best decision we ever made aside from getting our first yorkie in February 06.
Topher (our first and such a loveable, snuggle bear) has become so much more well behaved now that he has a little sister. (He was just over 1 yr old when we got his sister). He's not bored anymore so he definitely gets into less trouble!
Sophie, she's almost 18weeks old, has brought so much joy into the house...and she just ADORES Topher.
The only downside I can see would be travelling with two. I can see that being a
bit more difficult, but as with anything else,
it's all in the planning. There are ways, I'm sure, that you could do it that would make it less stressful.
As far as difference with size and one hurting the other...Topher is around 10lbs and Sophie just over 3...a huge difference! LOL You do have to keep an eye on them so that the play doesn't get too carried away, but for the most part we have yet to have a problem with this. If anything, Sophie is the one to watch because of those sharp little teeth! She puts Topher in his place if he gets too rough so he knows his limits with her.
All in all it's been such a
joy having two. Twice the yorkie kisses, twice the snuggles, twice the laughter and twice the love. How can that be a bad thing??
Good luck with your decision. It's not one to take lightly (it's a decision that you have to live with for 15+ years) so make sure that you are making it for the right reasons and that everyone in the household (if there are others) is on board.
I hope this was helpful.