Well it's not just the w/o slider that's different it's the look and features. No hinge that will ruin the screen if broken. GB games cartridge! Theres so many things this thing can do and I would say I would want one.
Most annoying thing Nintendo has done is get rid of the GBA slot in the newer DS models. Sure, nobody buys GBA games anymore but on games like Pokemon (which Nintendo invented) you could transfer them over... Besides, GBA games were epic.