While this feature is interesting and can further optimize the time it takes to open a form there are some important limitations. That is if you scroll down to the bottom of the article it contains a table showing when the "read optimized form" is loaded. And you will quickly realize that if a form has client side scripts it cannot take advantage of this feature.
I tested this out. I took a completely vanilla invoice form and - as advertised - when I opened the record it opened in the nice and clean Read Optimized format.
I then went ahead and added a jscript web resource to the form. To be clear I just added the web resource that are "available to the form", I did not actually wire up any OnLoad, OnSave, or OnChange functions. That is, this web resource was effectively doing nothing.
After I published this, I onced again opened up the invoice form and the Read Optimized setting was no longer respected i.e. it opened in full edit mode. In short, the mere presence of a jscript resource will make the form non-Read Optimized capable.
I am sure there are reasons why it was designed this way. There is certainly some jscript logic that can be impeded by the Read Optimization. Although I guess I'm wondering why Microsoft couldn't have introduced a 7th form type (in addition to create, update, read, disabled, quick, and bulk) in order to target this form option rather than taking the "all or nothing" approach. Perhaps that will be accomodated in a future enhancement or perhaps I haven't properly considered the technical issues that would accompany such a feature...
Anyway, in terms of the practical usage of this feature in it's current incarnation - I have to say I'm a little skeptical.
First of all, it has to be said - what percentage of forms have no jscript acting on them? Jscript really brings tremendous flexibility to form rendering etc. to the extent that not many forms (at least the ones that I touch) remain jscript-less. And even for those that do not have any jscript acting on them - it is of course quite likely over the course of time that you'll want to add some scripting to the form to accomodate some customer requirement. And at this juncture - assuming the client has been happily using Read Optimization for this form - you'll have to explain to the client that this feature that they've now come to know and love will no longer be available.
So when all is said and done, I think I'll personally be employing this feature quite sparingly.