I finally got around to getting a metal cutting circular saw. Metal is like a foreign language in the cabinet shop. Everyone seems to cringe at the thought of having to deal with it?
I purchased the 8" Milwaukee 6370-21 circular saw when it was first introduced in 2004. This saw is corded and was specifically designed to cut metal profiles and sheets. It works well, however, after Festool released their aluminum blade for the TS 55 saws, I made a conscious decision to try something different.
I still use the Milwaukee saw for fairly thick aluminum sheet (3/8"-5/8") and stainless but the TS 55 really shines with the thinner profiles. Throw in the Festool guide rail and all cuts are absolutely straight.
The Milwaukee doesn't have a vac port so small metal chips can migrate to between the saw base and the sheet material you're cutting, leaving nasty scratches in the sheet material. I added a HDPE strip to the bottom of the saw base and that helps considerably, but sooner or later you need to pick out the metal chips that have imbedded themselves into the HDPE.
I'm curious that with the recent additions of the Festool aluminum blade & CMT metal blade for the TS 55, why you didn't go that route and gain the precision/straightness when using the guide rail?