Competition, at least in terms of marketshare, it good for the consumers as it creates pressure to innovate and produce better products. That being said, I still get a lot of satisfaction over these reports of Apple quietly taking the market from Samsung and other manufacturers, precisely because these other manufacturers are so dishonest in their presentation of both their own products and of the iPhone and other Apple products. When Apple entered this market, the competition was operating on razor-thin margins, which on some level precluded serious innovation (because it costs big money in R&D to innovate), and instead depended on selling huge numbers of phones to recover their investments and make a profit. Industry leaders at the time, such as Microsoft's Steve Balmer, literally laughed at Apple when they entered the market. There were initially some corrections (such as Apple lowering the original iPhone price by $200 after only a few months), but the product was so innovative that consumers accepted the price overall, and were willing to pay the "Apple tax" to have a premium product. An interesting issue that I don't see people talk about is that Apple generated a margin of profit that did not previously exist in that market; they single-handedly redefined the ceiling for profits in the smartphone (or even cell-phone) arena and then started rapidly claiming those potential profits. The iPhone became their most successful product in history and drove Apple to the position of most profitable technology company in the world.
Eventually, Samsung came along with the Galaxy series. Since they were unable to accomplish the kind of major innovation that sway end-users to buy their product, they augmented what innovation they were able to come up with by copying designs both in hardware and software that Apple had come up with. This allowed them to produce a product that, on the surface, offered the major features of the iPhone, but at a better price than the iPhone. Ultimately, this accomplished two things: 1) it allowed them to increase their velocity in terms of gaining marketshare from competitors, primarily at the expense of Nokia and RIM (but Samsung increased their overall velocity relative to Apple), and 2) it allowed them to increase their margins overall. This was interesting, because it ate away at profits that may have otherwise gone to Apple, which emboldened Samsung and gave them increasing marketing power. Eventually, Apple sued them and inevitably won, but the ~1 billion dollar settlement (that Samsung might eventually have to pay Apple) was a relatively small price to pay for the overall increase in profits that this new tact was gaining Samsung.
The problem with Samsung's approach is that it is self-limiting. By copying Apple, they are appealing to a market that want Apple products, but, for whatever reason (usually price, but include other factors such as investment in the Android ecosystem), cannot make the commitment to buy an Apple product. As the remaining (non-Apple, non-Samsung) marketshare is claimed by these two companies, the trajectories, velocities, or whatever you wish to call it will inevitably decrease. At some point in a two-horse race, the market leaders must inevitably run out of any extra marketshare to target, and must then attempt to take marketshare directly from the other competitor. Unfortunately for Samsung, there are more people converting from Android to iOS rather than the other way around. As a result, it is inevitable that Apple will win this race, barring some significantly new innovation from a competitor (Samsung, Microsoft, Amazon, etc.). However, Samsung will, at that point, own enough of the market that their mobile product line will still be a major source of income to the company.
In the above case, Samsung doesn't lose, because it is a huge, global organization making thousands of products (everything from microwaves to Oil-tankers), and as such, the smartphone market is simply a way to increase its cash reserves for the next investment it makes. However, while Samsung doesn't exactly lose, Apple does win, because it makes only a handful of products, so the iPhone represents the large percentage of Apple's bottom line. Assuming Apple can continue to innovate, and can continue to capture marketshare, they will continue to enjoy wide margins, which will result in the continued production of amazing products for end-users, assuming the market pressure remains. Without the market pressures from companies like Samsung, Apple would cease to have a *need* to innovate. If all the competition folded, and ceded the market to Apple, we would start to see Apple products being release less often, with less innovation, and with less quality. Apple, like all companies, are in business to make money, not for altruism toward their customers. This unlikely scenario would allow Apple to continue making the high margins it currently enjoys, without having to spend the billions of dollars it is currently spending on R&D. The only loser in this case is the consumer buying this product, since they become locked into a high-priced product that no longer benefits from innovation. This is the disadvantage of a de facto monopoly.
All that being said, I have been an Apple iPhone user since July 2007 when I walked into an AT&T store to see what all the fuss was about with the new Apple phone. Once I realized I could get the "real" internet and not that WAP garbage that other manufacturers offered at the time, I couldn't leave the store without one. The halo-effect worked on me as well; I now have virtually all Apple products with the exception of one home computer that will eventually be replaced by an Apple.
I do enjoy seeing Apple win, but I hope the competition never goes away, because the continued innovation is a bigger victory for me than seeing Apple win the race. I want this to be a close race that never ends, with Apple always leading by a nose.