It's not just a feeling, I'm a professional programmer with a over 23 year
professional experience and I don't just feel, but see and know, here is a
difference. If you spent a very long time writing COM+ objects, or compiling
something for the VB then your registry starts looking like a trash can.
Also if you install some crazy apps to test them and then have to check and
delete them manually searching for the dead entries in your registry,
changes that you've gotten, then one day you will realize yourself that you
need to automate this job. The usual time to leave of my system is from 8-10
months to maximum one year. Step by step my computer becomes more and more
jerky and I either reinstall everything or rather restore the system drive
from some old generations of my backups using Acronis. It's fast, convenient
and safe to get everything back in an hour-two with just one disadvantage to
be having to reinstall everything installed after this backup as well as to
make missing options, tweaks, etc. I'm not new to the registry cleaning and
I was using different tools from time to time to extend the life of the
system. I just wanted to know what's the best and most current on the market
now, that's it. I actually didn't want either expect to hear a lot of
messages like - DO NOT DO THAT, etc.

I will keep doing that anyway. We
have our own tool written in our company to clear the lost COM+
registrations made by MS VB compiler. But it's not always enough.
P.S. I'd agree that the registry cleaner is not required for a computer
user, it's very easy to kill the system making any inappropriate changes,
but it's required for a professional programmer who plays with this stuff
too often and actually knows what he's doing.