suppose i want to use external graphics controller like SSD1963, because it has inbuilt 1215Kbytes of SRAM. so can you tell which would be cost effective, display with controller or display with without controller.
Maybe the key question here is not "which board..." but "does such board come with example software allowing to compare...".
ST is probably not really interested in producing such, as they want to sell thechips with LTDC (read more expensive). For example, the display used on the 'F429 Disco has a QVGA display with controller which can operate either with external and internal controller, but AFAIK there's no example code using the internal-controller mode (and the board's design is not optimal to showcase that mode either).