In my experience I've noticed these two pesky features while working in translations projects.

1) Target translations generated from a Word 97-2003 document (the ones with the extension .doc) as source won't include the comments. My advice: Before starting your translation convert your .doc source document into a .docx (Word 2007-2016). Then, you will see your comments in the generated target translation. As you know, sometimes comments are as important as the translation and something you can't do without.

2) When choosing "ES Spanish (International)" as source or target language, Studio 2017 (and 2015) uses a non-standard language culture (ISO Language Code-ISO Country Code) es-x-int-SDL, unlike es-AR (Argentina), es-ES (Spain), etc. (See http://www.fincher.org/Utilities/CountryLanguageList.shtml) This simple fact will not allow you to review check spelling and grammar unless you do some tricks explained somewhere else in this forum. My advice: for Spanish, don't bother with choosing Spanish for a specific country, just choose Spanish (Spain, International Sort). I know some colleagues would argue with me on that, but this works very well for me. At any rate, avoid choosing "ES Spanish (International)", the item in gray without a national flag.

I've commented about this in previous months.