Disadvantages of micro cases?

Hi all,

I built my first system for myself last summer and went with a pretty large case -- antec 1200 -- and am generally very happy with my build.

I'm now looking into building one for my gf, and as it turns out she has some very different priorities than I did when building my machine! In particular, she cares quite a bit about keeping the case small and, if possible, quiet. She wants to go no larger than her current desktop, which is a bit smaller than a mid-tower.

That leaves me with three options:

1. Lian-Li PC-A05NB's mini tower case -- it seems that there are very few cases available in this size now, and this is the most reasonable that I could find.

2. Convince her to go a tiny bit bigger for something like an Antec 300

3. Go really small with a micro case


Before I settle for option 1 or 2 I want to get a bit of a better understanding of what I'd be getting myself into with option 3.

Obviously micro cases require specific motherboards and will limit the size of the GPU. Other than that, is there any major drawback that I need to know about? I'm not planning on building a performance monstrosity -- she doesn't even want it overclocked. She's mainly going to use it for MMOs and PC RPGs (elder scrolls series and such), but she'd like it to last for a good four years if possible. I have a $600-1000 budget, give or take. Do you think that given these factors the micro option is something we should consider?