I used to but I dumped it for Trados. It's free now as apparently Ryan is sick so he stopped developing it although when I had a major issue and brought it up to him in person when I saw him at a conference, he didn't do shit anyway. For a programmer, he is a good translator!
I mostly dumped it because it didn't work properly in Excel 2013 (kept crashing) which is the issue I raised with Ryan. But even then, it only grabs cells, not sentences within the cell. So say you have the following in one cell:
Instead of grabbing one sentence at a time, in this case 学生ローン詐欺のスパムはさまざまな形で届きますが、負債額の軽減、整理、債務の免除を謳っているのが一般的です。as the first sentence, it'll grab the whole lot. So say you've translated all or some of those sentences, or similar sentences, Felix won't give you any matches.
I also don't like the revision function in Word. You have to change to Edit mode and then highlight that sentence. Trados has an advantage in that all sentences are lined up side by side (source on the left and target on the right) so you can see the J at all times and revise the E at any time. Concordance search is also better in Trados. Trados also populates the target column with matches and automatically populates the target column with 100% matches and moves on to the next line. If you have lots of 100% matches in a row, it is VERY fast. And it tells you your progress. For me, this alone is worth the 70K price. Trados has other analysis functions as well.
The best thing about Felix is the way you can create a TM in Excel if you have Source - target columns side by side. Although that no longer works for me anyway....
That said, very very occasionally if I have a large translated Word file with a very small amount of J additions thrown in, then I'll use Felix. And as I say Felix is now free so why not give it a try? You can always save TM files as TMX and import them into Trados at a later date if you ever do start using Trados.
"Yous guys talk a lotta shit. I'm much more smarter than all a yous." - Samurai Jerk after being owned by the Let's Japan crew.