Are there typographical drawbacks to using .otf font files?

Recently I’ve been messing around with different fonts in LaTeX and tonight got set up with the fontspec package which allows you to use .otf fonts in your LaTeX documents (in my case compiling with xelatex instead of pdflatex). Given the presence of online .ttf to .otf converters, this opens up a world of opportunity in terms of font usage — particularly with the availabliliy of high-quality free fonts available from sources such as The League of Movable Type.

My only concern with this is that, well, it sounds a little too good to be true. One of the reasons I use LaTeX is because the basic typesetting is just so good. Sometimes people mention that one of the reasons this works is that LaTeX font files contain more information than basic .ttfs which allows LaTeX to fine tune character placement. I’m worried that using .otfs through the fontspec package might compromise typographical quality.

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So I have two questions, and my naive answers.

First question (.otf): Will the use of original .otfss through fontspec result in lower typographical quality than using, say, the default Computer Modern? By “original” I mean .otf files created by the type designers themselves, rather than automated conversion software.

My naive answer is no … mainly because I want it to be no! But I did install Linux Libertine, and the first thing I noticed was a ligature (Th) I’d never even seen before:

This gave me hope!

Second question (.ttf): Will the use of .otfss created through automated conversion software from, say, .ttf files result in worse typography?

My naive answer to this is yes. This is because of the partial attributions of LaTeX’s good typography to the complexity of its font files, implying that default Microsoft Word font files simply didn’t contain enough information to place the fonts correctly.