I'm according with you. There are many electronic gadgets to say wich is better. My sister and me was checking between DS, Playstation, Tablets and vtech Innotab and finally we decided by the Innotab because we think that have characteristc more appropiated for my 4 years old nephew. For example, we think that a DS is a smaller toy for a 4YearsOld hands and we was looking for an resistent educational toy, but I'm sure that we, as women, consider more important the educational aspect than for example a father, who maybe consider as a priority the graphic quality of the toy and the type of games. Good luck!!!
Educational look into the WIFI downloadable systems for networks characters and buy the extras. Entertainment like DS, need look at advancing DS to DS XL for Networks games. Now sell used games for reasonable price. Note the interest level and ablities in your two are different. Inno will not keep 8yrs attention but great for 5yr after added downloads and adapter.