The main differences between blade guide types can be boiled down to four factors:
(1) Amount/quality of support
(2) Amount of blade friction created from that support
(3) Ease of set-up and adjustment
(4) Durability and maintenance frequency.
Ball-bearing guides offer the best all-around balance of these four factors. Although they don't provide as much contact area for support as block or disc guides, they do maintain constant contact with the blade without greatly increasing friction. They are also the easiest to set up and tend to be the most durable.
Disc guides provide the highest amount of contact area for support, but as with guide blocks, they must be positioned 0.004" away from the blade, which requires some type of gauge to be used for proper set up. Whereas some disc guides are fixed, similar to block guides, our Euro-Style disc guides spin with blade contact, which greatly reduces friction and the need for regular resurfacing.
Block guides offer excellent support, but unless they're made from specialized materials to reduce wear or friction, they tend to fall behind the other guide types in all other categories.
