The 4006TSW is as heavy empty as our old 686 4" guns were. It can become a weight on the hip after a long day.
It also makes shooting the .40 S&W cartridge a more controllable experience than some other guns.
Dunno what you're experiencing with the functioning issues, though. How old are your mag/recoil springs?
The CHP in our state has used the 4006, and now the 4006TSW, for 20 years and has had nothing but praise for its performance in both shootings and training (and they have 9000+ shooters who shoot monthly).
The only real functioning issues I've personally seen with the folks using the 4006TSW's were brought on by shooter-related issues ... being an assortment of grip and maintenance issues. Overall, the 4006 platform has demonstrated itself to be one of the more robust, durable and reliable .40's ever produced. I've seen a couple of 4006TSW's feed and function just fine when the mag followers were installed backwards ... until the mags ran dry and reversed follower couldn't lift the slide stop lever and lock the slides back.
The machining and subtle design refinements over the years have produced a 4006TSW that is even better in some respects than the earlier models. By all indications they should run longer when it comes to their service life.
One of the fairly large agencies I know who was using 4006's & then 4006TSW's didn't have any issues to speak of until they let their guns reach the 7 year point without changing mag & recoil springs, at which point they started seeing a lot of functioning issues. S&W recommends replacement of those springs in duty guns at either 5 years (of the mags being left constantly loaded) or every 5,000 rounds fired. New spring solved that agency's problems.
As far as Tap/rack issues and the slide-mounted decocker/manual safety? Well, yes, guns like the S&W TDA's and Beretta's with the same design can require an adjustment in performing the drill compared to a slick-sided slide weapon. It can be a training & technique issue, sort of like learning to depress a thumb safety in order to fire a pistol. Kind of like making sure you don't derepss the HK USP's lever from cocked & locked down past ready-to-fire to decock under stress, too, if you aren't familiar and fully trained to use that variant transitioning from a 1911 user where it's okay for the safety lock (thumb safety) to be depressed until it bottoms out, so to speak.
Another alternative to a modified grasp of the slide is to use the optional spring-loaded, decock-only assembly (which the CHP ordered in their 4006TSW's). The TSW slides are already machined to accept this option. It eliminates the on-safe position of the manual safety lever, making it a decock-only assembly in which the levers are forcefully returned to the upward ready-to-fire position when they're depressed and released.
They're still a boat anchor, though, as is the 4566TSW ... which I why I chose to carry the compact alloy models as issued weapons instead of the larger all-steel models.
While I do tend to like the TDA design in a defensive weapon, it seems the new M&P pistol is probably going to reduce the interest in the all-metal among the existing gov users in the coming years. It wouldn't surprise me to see the eventual discontinuance of the TSW model line over the next 10-15 years as a catalog model line for LE customers. Who knows, though? Sig Sauer is doing their best to keep the idea of a metal-framed TDA service weapon alive and well ... unless their sales of their increasingly expensive all-metal models does the same thing to them when it comes to commercial sales that the retail pricing of the TSW's did to S&W's sales, and then there's the sales potential of the new P250 model to consider at some point.
Who knows?
