Welcome
Scrrem and Florida1098.
340PD and M&P340. You really need to go handle both. Ideally shoot both but it is not likely there is an M&P 340 in the rental fleet. I haven't seen one at any of the ranges I frequent.
I am surprised how many 340PDs there are at ranges though.
The sights alone on the MP sold me. The 2 oz decrease from the 642 was a plus. Stainless steel cylinder is a REAL big deal as most of the problems I have read about were cylinder issues with the PDs. I also haven't run into any crimp jump with the 2 ounce heavier MP with the .357 loads that is apparently prevalent with the PD in the lighter .357 loads.
I like the looks of the DLC coating and the logo execution on the MP better too.
$100 could go towards a nice set of CT grips.
Dollar an Hour-
Hogue Monogrips are just the greatest. They are prompting me to seriously consider a set of CT 305s. Laser with a full grip.
DougS-
Welcome and that's a very good price on the M&P340. I called S&W months ago and they recommend Hoppes Elite, no ammonia products. I have also been using CLP with no noticeable deleterious effects to the finish. The Eezox is recommended by Larry Seecamp as a prefered product on the Seecamp line.
Google Eezox. You will find details on the product and as long as there is no ammonia you should be fine.
http://www.thegunzone.com/rust.html
CLP and Eezox were the corrosion protection winners in this interesting test.
I am not so sure that the DLC coating wouldn't stand up to the ammonia. I think the ammonia deal is more relevant to the clear coats on the 642 and perhaps the blue/black on a 442. The DLC is tough stuff, but I'm not going to experiment.
Don't forget. Price of admission is 340 pics. Post em up when you have a chance.