The SW1911PD & SW1911Sc 4.25" models are worthy of consideration if you're looking for a Commander-size 1911-type pistol. The Scandium alloy lightweight frames are a noteworthy improvement, too.
The well proven S&W external extractor design probably isn't something to be casually dismissed out of hand, either.
Depending on your personal preferences, experience and training needs other lightweight designs and models may be worth considering, too.
I've been carrying and training with S&W TDA pistols at work for approx 15+ years, and I've purchased several of them for my personal use off-duty, as well. My original 4513TSW is a fine compact .45 pistol, and the CS45 isn't bad, either. I seldom carry either of them anymore, however, having gravitated to other compact & subcompact 9mm & .40 S&W pistols for common off-duty use, as well as a couple of 5-shot revolvers (1 chambered in .38 & 1 in .357 Magnum).
The M457/457S, as mentioned previously, is sometimes an overlooked workhorse of a .45 ACP lightweight, compact pistol.
While I like the Colt XSE pistol, and bought one this last year, I also picked up a new SW1911Sc 5" pistol. Of the various size 1911-type pistols I own (all Colts), I haven't owned a lightweight Commander in many years, and I decided I wanted a lightweight model for occasional off-duty usage. Considering the advantages of the Scandium alloyed lightweight frame I decided on the SW1911Sc, but with a 5" barrel. While I own shorter 1911's, I've always thought the 5" models had the best combination of balance and overall controllability for my needs, especially if I was going to be doing a lot of training/shooting.
While I selected the standard stainless slide and standard Scandium alloy frame, S&W just released their new railed frame version in the full size model. It offers a Melonite treated stainless steel slide with an anodized black Scandium alloy frame which incorporates their new Universal Picatinny Rail option. While I'd heard that the new railed frame had been adopted by at least one L/E SWAT unit, I wasn't sure when it would be available to the public market ... and now it apparently is:
http://www.smith-wesson.com/webapp/...selected=over&isFirearm=Y&parent_category_rn=