@demonics : I see this topic has less success. I think the question is too much precise. Maybe we could talk about legibility in general. i then would have things to say.

"Which is easier" ???

@demonix : it's not possible to change yourself your username, i contacted the Staff (Support/Contact us) who did it for me. Thanks Marc Pfeizer who is in charge of receiving and treating our requests.
I've not so much time and disponibility right now to develop my ideas about legibility. Maybe tomorrow...

@Umbreon: the topic was serif vs. sans serif at first.

I guess I prefer sans serif fonts for longer texts. I hate how many websites these days overuse Georgia.

Ah, okay. Sans serif is easier to read. Less ornaments.

On readability: I think when designers qualify a work to be readable or not, it's an abuse of language. Cause actually they mean "easily readable" and more or less the exact replicas of some standard shapes established long ago or with the less possible distortion from them. This explains why 80 percent of the pro fonts are boring and similar.
I personally think the readability not to be envisaged as the absence of distortion from the standard shapes, but as the logical clarity of this distortion, would it be an important one. This logical clarity can be expressed in different ways and approaches : scientific, esthetic, abstract, or even emotional but in a clearly defined way. The more the distortion is important the more it demands efforts to our formatted minds by years of Arial and Helvetica diktat, but demandind mental efforts does not mean illegibility, as suggests the community of the designers whose initial goal is to "sell" objects with their messages. And who would have the desire to buy it demands any effort to the mind to capt the message saying to BUY ? It HAS to be very close to what people "already" know, that's why generally typography in town is so boring and not creative.

A little late I suppose, but I have my own theory about legibility: The human mind was meant to read handwriting. It pays attention to the ends of the letters and how they flow into each other, and this would explain the noticeable (although small) advantage of some serif fonts, like Georgia, over some sans-serif fonts, like Helvetica. I would have to say that despite all of its swashes and complexity, rioso Pro is one of the most legible fonts I know of, at least on paper.

Sorry, I meant Brioso Pro.

Brioso Pro is a real beauty isn't it? Classic proportions with just enough of a script feel.