Does T5008 replace the need to enter same data in Capital Gains summary?
Not exactly, the T5008 reports some of the same data that would be shown in your Capital Gains summary. To be more specific, it is a statement of securities transactions; meaning the slip deals with legal securities like: Debt obligations, options contracts, shares, treasury notes, or bonds. Furthermore, there are other uses for the Capital Gains summary that can reflect other different amounts. Like disposal of real estate/properties, or rental income. Therefore, it is important that you do not only use T5008's data as a comparison, and to make sure other capital investments (That are not securities) are reported. For more information on this topic: TurboTax - T5008 Slip