Is sizing fonts using “em” still relevant?

Question

Those of you who use em when sizing fonts will know that they can be a headache when dealing with nested elements, and having to make the px -> em

Answer 1

I have built full em zoomable sites in the past. In fact, every dimension in my company site ( http://kingdesk.com ) is em based. In all my recent work, I have abandoned such practice for four reasons:

1. EM Maintenance is a b*tch. It is one thing to get the math right on nested elements during the initial design, but reorienting yourself after some time away is burdensome – to the point of just puting in fixed units at the expense of breaking the em-zooming effect.
2. Browsers have come a long way in the past 2 years. The current version of every major browser supports page zooming natively.
3. It is true that these sites are less accessible to visually impaired users in IE6, but there are abundant freely available tools for them that resolve this issue. If there is not a reasonable alternative, I have a moral obligation to facilitate their need. If there are 4 ADA accessible ramps to my front door, I'm not going to demo the steps and replace them with a 5th.
4. I figure it saves me 20% in my design time.

I now design exclusively in fixed units, and have never once had a problem or complaint.

Oh, and if you're wondering, I no longer try to make sites look pixel perfect in IE6. They are still navigable, and decent looking. But time moves on and 9 year old browsers receive the attention they are due.