I've used it for a decade and it has always worked great. I'm very happy with this software. One slight glitch I have is to do with Safari. Ever since Safari 5 reared it's ugly head the tab triggers of TypeIt4Me are wonky when dealing with fields inside Safari.

I checked out the demo since it's on sale in the app store. I had high hopes for an alternative to TextExpander. It doesn't seem to be working on Lion very well. I was able to add a single expansion but it wouldn't let me add any more. Back to TextExpander... :/

Responsive developer— absolutely! Riccardo is terrific. I've told him many times that I am so use to TypeIt4Me that I almost couldn't live without it. I just do so much with it, without even thinking that when I am without, it is like anything else in life, that is when you realize by seeing all these sentences with abbreviations (not expanded) how useful it has become. I can't remember the last time I've typed my signature, phone number and many many other items. It just works!

I bought an upgrade to TypeIt4Me back in March 2002. I don't remember when I bought my original copy.
In 2006 I donated to Textpander, which became TextExpander. At one point I also got Typinator. I stopped using these 2 since SpellCatcher also provides text expansion, but a few days ago when TypeIt4Me 5.1 came out I decided to check it out, since SpellCatcher does not work properly in some applications (e.g., Firefox 3.x). This is NOT SpellCatcher's fault.
The downloaded file did not wok on my system (PPC), but as usual Riccardo Ettore's support was excellent. He sent me a compatible version, I tried it, and quickly paid the upgrade fee. Superb customer service.
All of these programs are quite similar. I can't say anything negative about Typinator or TextExpander. Their upgrade fees are roughly 42%-50% more expensive, though.
TypeIt4Me has some great unique features, such as "Strip 's' for plurals." It also offers quite a bit of options for the user, so it's a good idea to read the manual.
I had some problems when applying labels to my clippings. For example, let's say that I wanted to use "Name" as a label. As I typed, the label became something like "NNaNamName" Restarting the application solved this, but I had to do that multiple times.
Creating a nested clipping presented similar issues. This could be just affecting the particular build I'm using, and again it was easy to work through it.
I don't recall the specifics that made me abandon Typinator and TextExpander other than their redundancy with SpellCatcher, but I'm glad I gave TypeIt4Me another try. I'm using my SpellCatcher shorthands along with my old TypeIt4Me abbreviations, and for AutoCorrect I use the TidBITS AutoCorrect dictionary with the addition of SpellCatcher's own dictionary of words to correct, so roughly 3950 words are included. It was easy to set up, so far works on every application I've tried, the upgrade fee was very reasonable, and support was excellent. It can also be customized for specific applications. Highly recommended.

Still lacks the one thing that I personally require which is syncing across multiple macs.

If that ever comes about I will try it again.

Most recent version posts only a blank screen when the pref panel is selected (Typeit4me 4.2 purported to work with Snow Leopard but no go here). No apparent solution in sight (none offered in response to two email reports of this problem). Reinstalling 4.1.2 (as per prior comment) corrects the problem -- but that version is not available in the links on the download page on the developer's site.