Highlighting has always been tricky because it depends, in part, on what the pdf thinks is an actual word/sentence/paragraph. Some pdfs have ugly "under the hood" formatting and what we *see* as line breaks/word breaks may not be encoded as line or word breaks.

That said, I usually have to try 2 - 5 times to get exactly (and only exactly) what I want highlighted. I've had little problem with annotation, and lag measured only in seconds not minutes. To be honest, I tend to just underline, scribble or otherwise annotate a section of text rather than highlight it.

To test for comparison, maybe Entourage would send you a pdf they know is formatted well, and you could try highlighting that to see how easy it is to select. That would give you an idea of optimum performance to expect. I know in the early days of us receiving our machines, they also offered to take a look at specific pdfs we were having trouble with to let us know where they thought the problem was. You could try sending them the pdf to look at on their end.

Is this a very large document? (Like a textbook?) A lot of graphics? Did you create the pdf yourself by printing/exporting to pdf, or is this a professionally-created pdf download? Are you having this trouble with multiple different pdfs or just one/some in particular? Is there any pattern to the types of pdfs giving you the most problems? Information like that might help others troubleshoot your problem.