I need opinions about Shure FP filed mixers
 

Are FP32,33,42,43 - any good? What do you like; not

I've got the 33. It's been a workhorse for a decade now. I wish it had another input, but that's a rare need in the long run for me. It has all the pro features I need. If you decide to go with BDS power distribution, I recommend you go with the Li-ion NP-1 batteries. They last a lot longer, but they are also lower noise than the Ni-MH batts.

Paul,
FP32 is very old kind of noisy, FP-33 quieter than 32. Analog VU display is kind of old fashioned in the digital world. Most people are moving towards Sound Devices if they don't like the Shures.

If you have the money, the Sound Devices 442 is a nice mixer, and you get one more input. But, it's $1k more than the FP-33. I sort of like the Analog VU meters. Maybe I'm just old fashioned.

FP33a is the newest, skip the others. these mixers want to be juice at 18V minimum, they like 24V. if you try to run them on a 14.4V NP1 or similar external, you'll not be a happy camper. the channels will easily clip, the limiters don't work right. all that goes away with hot power. been there done that and its why I put together my own 24V/12V bag power system. even the dual 9V internals should start out at about 20V or so hot.... and discharge down to about 14 where you are in the bad performance zone.

the main meters are fairly useless. the channel LED's are more useful. the main meters have a dampening that matches nothing else. I have tried the mod to slow their response speed down which might make them averaging... or at least have some match to the camera.

that said, its pretty clean, and works fine if powered correctly.

there are a lot of 422's used on the market these days since the new 522 is out. as long as the size and wieght aren't a problem, you wouldn't go wrong with one.

I still have an original FP32 (not the unrepairable 32a) I still use it for back-up or hazardous duty. It's been all over the world in many hostile environments. (weather and social unrest) Aside from replacing the master and HP pots, it still works and sounds decent. I occasionally come across an old PBS doc. I've worked on and the interviews sound nice, especially when the ambient BG is higher that the 32's noise floor. The mic pre's sound decent with a high output condenser mic like a 416. (channel high/master low) As already pointed out, It was, in it's day, the defacto ENG mixer. If you could find a good used one for less than $400usd or so, I would get it.