If some of the Allegiance's primary hull was tweaked here and there (Impulse Engines, aesthetics of the retroized bridge module and areas below, maybe also more square-than-triangular escape pods since they aren't stacked next to each other) and maybe the warp nacelle grilles (maybe give it more TNG-era standard aesthetics, maybe keep it unique as it is, so perhaps I'll go for the latter), it would be a very-appealing design (although it still is without such changes, just not as much so for my taste), and perhaps better suited as the Enterprise-E than the current Sovereign-class design.