I have used iVI and also iFlicks - I like both.
iVI is my first choice, because..
1. It’s better at finding movie & TV show meta info (correctly) the first time.
2. It identifies and encodes 5:1 audio, and makes a properly balanced stereo copy at the same time. No more music that blares with vocals you can barely make out.
3. If you set up two drop folders, one for movies, the other for TV shows - iVI will process them and then place them and/or create folders (including [showName]/[seasonNumber] for you.
4. It only re-encodes audio/video when it needs to - since .avi, .mkv, etc. are realy just container codecs; which means many times your MKV or AVI file is really in an Apple Friendly audio and.or video codec. In this case iVI will not need to re-encode the compatable parts - this saves time, and processor power, and preserves the highest quality.
5. iVI lets you set limits on file sizes for TV and Movie conversions.
However, iVI uses theMoviesDB and theTVshowsDB for lookups, which sometimes have returned no results (I think because domain lookups may be involved), while iFlicks uses IMDB (probably ip-based); so iFlicks is more reliable even when the others are not up. Its not a frequent problem, but when it is, I then flip to iFlicks for awhile.
Although iFlicks has smart filters that are more powerful than iVIs, you don’t really need these with iVI - you will though with iFlicks.
These are both great apps - and I would strongly recommend you get both.
You will discover that iVI is going to be your first line choice though - i’m quite sure you will agree once you try them both.
99% of the time I use iVI - and HIGHLY RECOMMENT IT.
Both play well with iTunes - with or without external itunes storage drives - equally well.