The title comes from the oft-repeated phrase, "I don't need 5 frames per second shooting for my style of photography." There have been many honest and genuine posters on dPreview and elsewhere who have professed that they don't "need" much more than 1.5 to 2.5 frames per second from their digital camera. To those honest and sincere individuals who do NOT "need" fast frame rates,I want to use a variation on the James Carville quote, and say,"It's not the frame rate, it's the AF system,stupid." That reference is of course a variation on Carville's phrase, "It's the economy,stupid." And so, in that vein, let me say that the "need" many profess for a camera which has a frame rate of 5- to 8-plus frames per second, is based not so much on the need for a high firing RATE per se, but on the need for a FOCUSING SYSTEM that is fittingly professional and capable for a camera that is expected to perform as a FULLY professional tool,with no excuses about the shots that got away.
Let's make it clear--the reason the Fuji S2 and S3 and Canon D60 and D30 and the Nikon D70 were/are poor sports/event/low-light cameras is that they have at their hearts merely consumer-grade autofocusing systems. The EOS D60 had,unfortunately, some real focusing problems; and yet still, the D60 sold as many units as Canon was able to make, and upon the discontinuation of the D60 Canon still had people clamoring for units to buy from dealers, yet the camera had already been superceded by the EOS 10D, which sold imminently well,and which had a "bit" of an improved AF system. Following the 10D, Canon very quickly tried to address the D60 and 10D focusing problem situations with an ALL-new, 9-point AF system for the 20D. Canon later took the 20D's 9-point AF system and added six,additional,hidden AF points and put that system into its afordable new 5D full frame d-slr. See the trend here? Canon has had to continuously address autofocusing problems and issues with its high-end amateur/semi-pro class cameras.
The "professional cameras", those D-SLR's like the Nikon D1,D1h,and D1x,the Kodak DCS 720 and 760 models, and Canon's very first full-fledged "Professional" D-SLR, the original 1D--all of those cameras were built around flagship-grade autofocusing motors and autofocus modules worthy of inclusion in state-of-the-art cameras. Besides fast frame rates, like 4.5 to as fast as 8.2 frames per second, cameras like the old Nikon D1 and D1h and the Canon EOS 1D Mark II and Mark IIN and the Nikon D2h,D2Hs, and D2x--all of these models were/are built around the MOST-responsive, fastest-REACTING shutter release systems, and the fastest and best shuuter and mirror actuation and mirror return systems that Canon and Nikon have been able to design and build. Shutter release lag times, autofocus speeds,predictive AF abilities,mirror latency times, ALL of these speed-related things help to SUPPLY the autofocusing detection modules with DATA as RAPIDLY as is POSSIBLE. Modern D-SLR focusing systems using phase detection respond more quickly and just "better" when they are supplied with a lot of data, rapidly. Modern D-SLR autofocusing systems can NOT do any work while their mirror is in the up position....the mirror has to be down to supply information...the faster,and the more times per second the mirror is down, the more-rapidly the AF system can be given fresh new data in order to do its work.
The advantage of a Nikon D1- or D2-series, or of an EOS 1D,1D-II or 1D-IIN lies not so much in the high frame per second rate, but in the ultra-FAST response times of the entire machine, and most especially in the high quality and superbly-engineered autofocusing systems one buys when he or she lays down $4000 to $5000 for a camera. The Nikon D2x is probably the single fastest-reacting non-pellicle SLR camera ever made for commercial sale and wide distribution. The shutter and mirror and AF systems operate exceptionally rapidly in the true PRO-grade Nikons and EOS models which have been targeted at the sports/news/event photography segments. In other words, the reason so many of us want the fast-firing cameras is not for the capability to trip off shots at 5 to over 8 frames per second...nope...what we want is the FOCUSING abilities that are available only in these fast-firing,fast-handling,top-tier models. We wish to avoid the constraints imposed by the types of focusing system that the EOS D30 and D60 were plagued with, and the lower-end AF modules and motors found in other low-end bodies from Fuji,Nikon,Sigma,and Kodak. At times, manual focus is fine. At times, center-only AF with one cross-type sensor is adequate. But when pushing the envelope,or shooting to capture potential once-in-a week or once-in-an-event moments, the second-and third-tier AF systems may mean out of focus frames, or buffer depth of two or three or four images, and that simply isn't going to cut it halfway through the first decade of the 21st Century. It's not the frame rate, it's the focusing system,stupid. Plus the write speeds, the review speeds, the high-performance battery packs,the vertical grips with full sets of exposure and focusing controls, the ultra-short shutter release lag times, the brief latency times, and the superior build,fit,finish,and viewfinder systems. Plus the deep buffers, the robust build quality, and the top-drawer flash control protocols and the dedicated, manufacturer-specific flash units...it's not the need to have a camera that shoots at five FPS that makes one pay more money for a camera that shoots five FPS...it is merely that the cameras which shoot at five FPS happen to be some of the very BEST overall cameras. And it's been that way for years.