When it comes to the Roman Missal, propers and readings really need to be in the same place. Having the two separated as with the liturgical books is too artificial for actual use --- it would be a lot better to place the Introit, the Collect, the Reading, &c. in that order, as in every Daily Missal ever. Magnificat does this, too.
I have a 1962 English-Latin Missal --- a few of them, now that I think about it --- but it would be so convenient to see the translation so near the actual text.
I have several other suggestions regarding the collection of Roman Missals:
1. Can there be older versions of the Roman Missal available, also?
2. Can there be missals of other Rites available? Dominican, &c.?
3. Also, for things free online, this really is very pricey. If there were more content, though, I would not hesitate so much.
4. Why not simply provide a Daily Missal, as does basically every print publisher? Why keep the missals and the lectionaries separate?
5. What about using the Corpus Christi Watershed missals? Beautiful line art, for what it's worth.