Razvan, you are very much off-base on that statement. Though entry-level Sony DSLRs using CCD were very poor high-ISO performers, the A500 and A550 sensor (the very same used in Nikon D90, Pentax KX, etc) is an excellent performer at controlling noise at high ISO. It is also a viable choice for sports as it is capable of shooting at 5 frames per second with full focus and metering, or up to 7 frames per second with focus and metering fixed on the first shot...it also has in-body stabilization which will render some excellent fast primes fully stabilized, something that you cannot get in some other brands.
With my A550, I shoot regularly at up to ISO6400 with no problems retaining detail and avoiding heavy noise, with solid color fidelity as well. Even shooting in straight JPEG, no RAW conversions, and retaining shots straight from the camera with no additional post processing or noise reduction, I can make sellable large prints from ISO3200.
Here's ISO3200 straight from the camera, JPEG, no processing:
Here's the same at ISO6400, straight from camera, shot in JPEG, no processing:
Of course, shooting at night, underexposed, at high ISO is harder than daylight...but I also shoot a lot of handheld night and low light photography, also mostly in JPEG, and without additional processing necessary.
ISO6400 extremely low light sample:
ISO3200 nighttime sample:
Many people dismiss Sony DSLRs because of some personal reason against the brand Sony...and that's their prerogative. Personally, I don't feel it's appropriate to condemn, dismiss, overlook, or convince others to avoid a product solely because I don't like something some division of the corporation did in the past, but many others disagree, and are happy to dismiss Sony as a recommendation or consideration. Again, fine by me - but spreading wrong information is the only thing I will make effort to correct. Previous Sony cameras were poor high ISO performers, and therefore they were easily dismissed by other brand users and rightly so. But several Sony models have come out over the past year which are at the top of the APS-C performers for high ISO (not better than, but as good as).
Those folks not familiar with Sony, and used to dismissing them with the same old lines, are no longer correct when it applies to these newer cameras. There will always be strong bias against Sony - so many dislike them as a company for past transgressions in different divisions and cannot separate the two completely different industries - and reviewers often approach Sony cameras with preconceived biases, expectations, and dislikes...this often taints the reviews or causes them to seem mildly less favorable. Advantages of Sony cameras are often not really emphasized - features missing from Sony cameras which are available on Canon or Nikon cameras are listed as 'cons', while features unique to Sony and not available on Canon or Nikon are NOT listed as 'cons' in their reviews. A mild double standard, but again life will go on and there's really no way to completely eliminate bias. Some might say Sony is just getting what it deserves, and will have to work hard for years or decades to win back favor...I don't own interest in Sony so it doesn't really bother me either way.
But making blanket statements which are untrue are misleading, and I will always work to correct those.
Sony DSLR-A68 / Sony 18-250mm / Minolta 50mm F1.7 / Tamron 150-600mm / Minolta 300mm F4 APO
Sony A6300 / 18-55mm F3.5-5.6 / 55-210mm F4-6.3 / 10-18mm F4 / 35mm F1.8 / 16mm F2.8 / FE70-200mm F4 G OSS / FE70-300mm F4.5-5.6 G OSS / via manual adapter, lots of Pentax K mount, Konica K/AR mount, and Leica M mount manual lenses