While imitation is the sincerest form of flattery, I think it just coincidence as both pistols have features found on pistols of newer design, yet incorporate some of their own design features. Both had to be designed with USSOCOM Combat Pistol program specs in mind. The USSOCOM Combat Pistol program is now on indefinite hold due to budget constraints and probably some politics. Beretta recently recieved and order for a large number of replacement M9's.
The Taurus design is an outgrowth of the already existing 24/7 line while the S&W is a modification of the S&W M&P line, which was another modification of the Sigma Line which was S&W's answer to the Glock designs. (Glock sued S&W for some patent infringements.)
S&W Prices always tend to be more than other competing designs and my experience with S&W quality has been quite variable. (My early S&W M39 and M19 were terrible, as they were made when Bangor Punta owned S&W and Quality was generally horrid, however my inherited S&W M10-6 and my S&W 4506 are excellent. Current S&W Quality also seems variable. I've seen both good and bad on current manufacture.)
Call me biased, but I prefer the grip design of the Taurus version and I would trust their quality more. The only other one I would prefer would be the HK45, which is a mildly modified H&K USP45.
It is simpler than that. Taurus actually builds most of Smith's components in brazil and ships them to there manufacturing facility. That is why I always crack up when people run down taurus and talk about how great smith is.
If you read the Taurus websites History page, it will clear up most of the rumors about Taurus and Smith & Wesson over the years. (read a clip from that Taurus webpage)
Smith & Wesson had been purchased by a conglomerate named Bangor Punta. In 1970, Bangor Punta also purchased 54% of Taurus. Thus, the two companies became "sisters". Smith & Wesson never owned Taurus. They were both independent companies. However, during the next seven years, a great deal of technology and methodology was passed between the two. What may come as a surprise to some is that more of what was "right" in Porto Alegre was sent to Springfield than was sent from Springfield to south of the equator.
1977 saw our present ownership buy 54% of Taurus outright from Bangor Punta. At once a quest to improve overall quality of Taurus product was initiated. Also, the company now began a dynamic expansion program.
Beretta had won a huge contract in 1974 to produce small arms for the army of Brazil. Part of the deal was that Beretta construct a Brazilian factory and use Brazilian labor. This they did, in the southwestern coastal city of Sao Paulo. When the contract ran out in 1980, Beretta sold the plant, literally "lock, stock and barrel," to Taurus. Taurus now owned everything that once belonged to Beretta, including drawings, tooling, machinery, and a very experienced work force. Taurus was in the pistol business, and immediately sought to improve on the Beretta design, resulting in the popular and acclaimed Taurus PT-92 and PT-99 9mm pistols.
You see also that Taurus has never licensed the model 92 pistol from Beretta, they bought it, redesigned it in 1980, followed by Beretta redesigning there model 92 in 1981 with some of the changes that Taurus made first (yes Taurus did it first).
Point being that Taurus, Beretta and Smith&Wesson have all had a working relationship over the years, which still continues today to some extent (its good for business). The OSS, S&W MP and a host of other pistols all resemble each other because of the requirments placed by the Government for the now canceled Joint Ops pistol.