I would agree. While I am on the fence about FTL (it all depends how it'll be added that counts here for me), I do believe some change to bigger ships should be made, including further change in their propulsion and effect of different blocks. Currently, as I've stated on occasion, big ships feel like upscaled fighters, with only difference lying in a few stats. The design and so on however can be very similar.
It's simply bad. With each ship, no matter what size requiring one crewmember and no big changes in demand for blocks, there's hardly any differentation in space battles, which are usually (at least for observers, according to rather popular opinion) slugfests where two groups/players keep pumping each other with ion blasts and the winner is the side with bigger ships/more blocks on their side. No difference in designs or alternative tactics worthwhile.
I wouldn't mind if mobility-wise big ships would be more susceptible to attacks by small fighters or boarding parties (though also only to a degree, small scoutships with tiny guns designed to damage their equal-sized brethren shouldn't be much of a problem for typical cruiser's shields, at least not without prolonged attack). It would require some differentiation in typical fleet, some escort squadrons and anti-missile batteries or flak cannon turrets for taking down enemy fighters/bombers).