Solid Block Activated Carbon (SBAC):
Activated carbon is the primary raw material in solid carbon block filters; but instead of carbon granules comprising the filtration medium, the carbon has been specially treated, compressed, and bonded to form a uniform matrix.  The effective pore size can be very small (0.5 - 1 micron).  SBAC, like all filter cartridges, eventually become plugged or  saturated by contaminants and must be changed according to manufacturer's specifications.  Depending on the manufacturer, the filters can be designed to better reduce specific contaminants like arsenic,  MTBE, lead etc.
  The advantages of SBAC filters include:
Provide a larger surface area for adsorption to take place than Granular Activated Carbon (GAC) filters for better contaminant reduction. 
Provide a longer contact time with the activated carbon for more complete contaminant reduction.
Provide a small pore size to physically trap particulates.  If the pore size is small enough, around 0.5 micron or smaller, bacteria that become trapped in the pores do not have enough room to multiply, eliminating a  problem common to GAC filters.
Completely eliminate the channeling and dumping problems associated with GAC filters.
SBAC filters are useful in emergency situations where water pressure and electricity might be lost.  They do not require electricity (like distillation) to be completely effective, and water can even be siphoned through them.
SBAC filters do not waste water like reverse osmosis.
Many dissolved minerals are not removed by activated carbon.  In the case of calcium, magnesium, potassium, and other beneficial minerals, the taste of the water can be improved, and some (usually small) nutrient  value can be gained from the water.
Simple, economical maintenance.  Typically an inexpensive filter cartridge needs to be changed every few months to a year, depending on water use and the manufacturer's recommendation.
This combination of features provides the potential for greater adsorption of many different chemicals (pesticides, herbicides, chlorine, chlorine byproducts, etc.) and greater particulate filtration of parasitic cysts, asbestos, etc. than many other purification process available.  By using other specialized materials along with specially prepared activated carbon, customized SBAC filters can be produced for specific applications or to achieve greater capacity  ratings for certain contaminants like lead, mercury, arsenic, etc.
  The disadvantages of SBAC filters include:
SBAC filters, like all activated carbon filters, do not naturally reduce the levels of soluble salts (including nitrates), and some other potentially harmful minerals like arsenic (unless specially designed and certified to do so) and cadmium.  The fluoride ion is also not removed by activated carbon.  If these contaminants are present in your water, reverse osmosis would usually be the most economical alternative followed by distillation.
As described above, hot water should NEVER be run through a carbon filter
As SBAC filters remove contaminants from the water they gradually  lose effectiveness until they are no longer able to adsorb the contaminants.  There is no easy way to determine when a filter is nearing the end of its effective life except that the 'filtered' water eventually begins to taste and smell like the unfiltered water.  The manufacturer's guidelines for changing filter cartridges should always be followed.
  To ensure that marketing claims are accurate, check  NSF International to see if the SBAC filtration system you are interested in purchasing is certified to significantly reduce the contaminants you are concerned about.

An example of a certified list of contaminants significantly reduced by a high-end SBAC filtration system
(** at 200 percent of capacity - that's after filtering twice the rated volume of the filter**)
 For Standard 042 - aesthetic
   Chlorine Reduction, Class I (actual chlorine reduction 99.9%)
   Particulate Reduction, Class I (actual particulate reduction down to 0.5 micron)
   Chloramine Reduction (actual chloramine reduction greater than 96%)
   Taste and Odor Reduction
 For Standard 053 - contaminants of health concern and measured percent reduction
   Asbestos Reduction >99%
   Chlordane Reduction >99.8%
   Cyst Reduction 99.9%
   Lead Reduction >98%
   Mercury Reduction >99.3% (pH 8.5) >91.4 (pH 6.5)
   MTBE Reduction 96.6%
   PCB Reduction >98%
   Radon Reduction
   Toxaphene Reduction >93%
   TTHM Reduction (Trihalomethanes) >99.8%
   Turbidity Reduction >99%
   VOC Reduction (volatile organic chemical) Reduction - you will see a long list of specific VOCs
   (individual percent reduction for the various VOCs can be found on the product certification
   sheet below, but most are 98-99% or more).
 For NSF Standard 401 - Emerging Compounds/Incidental Contaminants
   There are 15 contaminants on the list

A few SBAC filtration systems have also been certified for arsenic reduction: