First of all, the ZW-L (aka 6-37921) is listed as 620 watts on their website, not 720.  This is what I went with the older ZW-C (aka 6-32930) with 4 180 watt bricks, for that extra 100 watts.  But to get that, you have to buy 2 more bricks as the ZW-C only comes with 2.  Also, the ZW-C doesn't put out the full 18 volts to the track in command mode.  Don't know why, but it has been documented here on the forum as something to be aware of.  I get between 16.5 and 17 volts out of mine per handle.  So really it's 660 watts in command, but that's still higher than 620.  Also, the ZW-C can have issues when used with Legacy if it hasn't received the Legacy PCBA correction.  I do not know if mine has had it or not, but it was my understanding the symptoms were it wouldn't respond to commands.  Mine does respond to commands, but I always have to address it and turn up the voltage, even if the handles are all the way up (Not suppose to have to do that with the inside handles, at power up they are suppose to be at the voltage the handles are set at.).

So in summary, the ZW-C has more wattage, but takes up more room as you have to have 4 big external power bricks.  Also known not to output full power in command mode, and depending on the vintage of the unit, it may not work with Legacy.  It also does not have meters, unless you can find the add-ons, and then they aren't the best.  You can only get them used.  The ZW-L is all contained in the single unit and has built in meters.  It also works with Legacy without any mods.  Only ZW that can be bought brand new.  But it is a lesser wattage.

sinclair posted:

First of all, the ZW-L (aka 6-37921) is listed as 620 watts on their website, not 720.  This is what I went with the older ZW-C (aka 6-32930) with 4 180 watt bricks, for that extra 100 watts.  But to get that, you have to buy 2 more bricks as the ZW-C only comes with 2.  Also, the ZW-C doesn't put out the full 18 volts to the track in command mode.  Don't know why, but it has been documented here on the forum as something to be aware of.  I get between 16.5 and 17 volts out of mine per handle.  So really it's 660 watts in command, but that's still higher than 620.  Also, the ZW-C can have issues when used with Legacy if it hasn't received the Legacy PCBA correction.  I do not know if mine has had it or not, but it was my understanding the symptoms were it wouldn't respond to commands.  Mine does respond to commands, but I always have to address it and turn up the voltage, even if the handles are all the way up (Not suppose to have to do that with the inside handles, at power up they are suppose to be at the voltage the handles are set at.).

So in summary, the ZW-C has more wattage, but takes up more room as you have to have 4 big external power bricks.  Also known not to output full power in command mode, and depending on the vintage of the unit, it may not work with Legacy.  It also does not have meters, unless you can find the add-ons, and then they aren't the best.  You can only get them used.  The ZW-L is all contained in the single unit and has built in meters.  It also works with Legacy without any mods.  Only ZW that can be bought brand new.  But it is a lesser wattage.

Great information, I should have mentioned I run conventional and like to run long passenger trains,

Personally, I would get the new ZW-L (I'd like one myself, but can't justify it as the PH-180 bricks I have are all I need). New and better design, parts are available, warranty, etc. I think there are some things that go bad on the ZW-Cs and some of the parts are hard to come by. Also the PH-180s have been sold out for some time now and I don't know when any will be available again. Hopefully, later this year unless there is another delay or something. Some are reportedly selling used for a pretty high premium on ebay.

rtr12 posted:

Personally, I would get the new ZW-L (I'd like one myself, but can't justify it as the PH-180 bricks I have are all I need). New and better design, parts are available, warranty, etc. I think there are some things that go bad on the ZW-Cs and some of the parts are hard to come by. Also the PH-180s have been sold out for some time now and I don't know when any will be available again. Hopefully, later this year unless there is another delay or something. Some are reportedly selling used for a pretty high premium on ebay.

Thank you for that, I was unaware that I would have to add 2 more bricks to equal the power of the newer model this makes the ZW-L seem more cost effective.

You are welcome. Good luck with your selection.