My dedicated 35mm film Canon 420ez arrived with the postman this morning.
I was a little optimistic about compatibility and had a few nightmares about using it on manual as many forums suggested but not actually made clear the results.

so anyways here are a few conclusions.

with the canon set to manual and the flash set with TLL removed , the flash worked perfect.
The auto focus on the flash does sync with the focus of the main body lens. The meter system built into the flash works automatically giving realtime meter reading to dial into the body of the DSLR.

The One thing that is a little off is the flash strength, but after reading the manual it's pretty much easy to work out.

Within 4 mins my camera was ready to take better flash based photo's for very very little money.

Of course not every dedicated 35mm flash will work the same, the one i have has metering,LCD etc.. to help with the manual mode.

I use a 420EZ with my 400D. I found after a few tests that it does what I want it to do. I always used the 420EZ in manual mode with my old EOS 5, so I didn't really see any difference. My only real gripe is the time it takes to regenerate between flashes in manual mode.

Can you set it to fractional powers? If so it will recharge quicker.

Can you set it to fractional powers? If so it will recharge quicker.

Yes, down to 1/32. I do use it on full power with a stofen diffuser a lot though.

Can you set it to fractional powers? If so it will recharge quicker.

yes if you have it on 1/16 or less and use Ni-Cad it recharges almost instantly, quick enough for the 3fps my DSLR anyways.

You can pick up a ultra high end 540ez for less than £40 where as the Dslr 540ex sells for well over £150.

the 540ez can do 1/128 on the flash.