Having had my computer go belly up, twice, trying to install 10.5.8 I’ve wiped my drive and have decided to stick with the original installation disk version, not installing any of the updates. Besides saving myself a whopping amount of hard drive space I’m finding the whole system, especially text, to be a lot faster and more responsive. A few text based programs have told me I should update to 10.5.5 to get better text functions without actually telling me what these are. Just out of curiosity does anybody know what I’m supposedly missing out on? 
10.6 
Except, in my experience the text system is even worse in 10.6 than .5. Who knows, maybe Apple doesn’t know how to code an efficient automatic text replacement feature (which I have no interest in anyway and wish I could just turn off entirely).
This is indeed a major pain in 10.6. Even if you switch off text checking, all the text checking functions get called every time you hit a key, if only to check whether they should do anything or not. The text system has done nothing but get slower and slower since Tiger, sad to say.
Just as I thought. Thanks both. Going to stick with it and ignore updating. Prefer the speed to unknown ‘improvements’. 
Is it too much to say the Apple is not very text oriented, and never has been?