This chronically buggy piece of crap is brought to you by the same folks who bring you Internet Cleanup, another chronically buggy piece of crap.
I've used both, on and off since their inception, and have rarely experienced smooth going. I've now washed my hands of both of them. UGGHHH!!! NEVER AGAIN!!!!
First there was Aladdin which was taken over by Allume, and now it's Smith-Micro that owns these horrible apps. And none of the three had/has a clue how to make SC and IC work well.
Both Spring Cleaning and Internet Cleanup should be given a decent burial, and then, perhaps, rewritten from the ground up by developer's who really know what they're doing.

When Aladdin initially came out with this product many years I purchased it, given Aladdin stellar reputation at the time with such products as Stuffit combined with great support. What a mistake as this product was rotten at its core. Aladdin's attempt to fix this product slightly improved the interface but never address its basic problem which was it simply never worked properly. Personally I believe that this product contributed significantly to Aladdin's demise. In any case I eventually gave up on it and got rid of it - a decision that I have never had any remorse about doing.

If you subscribe to the concept that past history is a reasonable predictor of future results, I would suggest staying away from this product given its history, its current developer and previous reviews. The only way I would consider revisiting this product, even in a demo mode is if the developer emphatically stated that they threw away the entire previous code base and started over from scratch, retaining only its name. Even then I would be suspicious.

As for alternatives, I would take a look at Onyx and Applejack for free system cleanup products. For drive cleanup and organization I have found File Buddy hard to beat.

As for optimization, Mac's don't really need need it. However if you must, I find the best technique is to back up your data files and apps to an auxiliary disk; do an erase and clean install and then restore your file. An auxiliary drive generally will cost no more than software designed to do this and it has the added advantage that it can also be used for automatic daily backups.

I also HATE this software. I purchased it to clean up my hard drive. After installing Tiger, my Photoshop 7 acted up, which appears to be a common problem. It would take Spring Cleaning 3+ hours to scan the handful of megs on my HD, then it would take an additional 3+ hours to uninstall it. I had to do this several times to get all the Photoshop pieces off my machine. In total, it took me a week! Who has a week?? Not me. Uninstalled Spring Cleaning and will write own program instead. To add insult to injury, my rebate was denied - they didn't like the previous version# of my last anti-virus software. Too bad. A deal is a deal. If you only accept certain version #s, list them on the offer. Will not do business with mcafee/allume again.

Spring Cleaning 7.0 By Allume Systems

Alum is fitting...it will make you pucker thats for sure!!!!

SC 7.0 IS A TOTAL CRAP!!!!
I Am running Mac OS X 10.3.8 ON A PM G4 DGP ....It always crashes after it spent 3 hours to sort through my hard drive, and never saved any back up data and starts from the very beginning as if it was the first time it scanned my system. Once more... Kernal Panic ---> then a charming (( CRASH )) ...Then when i gave it a small simple task to carry out, it miss labeled things as corrupt or orphand causeing the files to change and be unreadable to there original programs. This program is total baby puke in a dirty diaper..Run for your Life! And to think i paid for this thing.
P.S. THERE UPDATE WON'T EVEN WORK AS WELL!!!!

Thanks. For some reason, I always attribute poor performance to pilot error. I tried SC6 and was left scratching my head, wondering WTF I did to so thoroughly screw-up this app. Glad to hear it comes pre-screwed.