Every weapon has it's limitations, the advantage with bullpups is similar lenght of barrel (which leads to similar accuracy and similar range) while enabling the weapon to be much shorter which is an obvious advantage, especially nowadays when a lot of the fighting is done in cities.May I find out what those bullpup designs are? I do understand that the bullpup is becoming a trend in military weaponry, but I do think that they have certain limitations. For instance the SAR-21 rifle (Singapore's bullpup rifle) is not ambidextrous. Further, bullpups have a tendency to eject too close to a person's face for safety. In that case, a submachinegun may be better.
The FN F2000 is fully ambidexterous, both the Famas and the Tar-21 systems can be configured for both left and right handed usage. The ejection is not a problem since it ejects to the other side, or in the case of the F2000: forward. The only moment when the ejection is a problem is if you are shooting from the other side of a cover but even then it can be easily negated by tilting the weapon so that the empty casings eject towards your chest instead of your face.