So some initial thoughts after a few weeks of playing...
1) Scale - its impressively good; everything seems to be as large as you would expect; I'm currently standing on the back of a condor next to my ares heavy fighter looking at a Gorgon Vanguard and it all just looks right and I like how the light filters and changes as you fly past other objects.
2) AI - Shocking, absolutely shocking; can't fly right, can't avoid obsticles; takes an age to go anywhere in a logical manner. Why do ships spin around a few times when leaving the superhighway?!
3) Fleet Controls - Again terrible. I want to assign wings for different functions and only have them launched when their parameters are met, e.g. capital attack wing should only launch when a capital is within sight and not before... all you can do is assign one of 3 terrible rules that don't really make sense.
4) Economy - Simulated is good, seems to work well; cut of xenon access to resources and after they threw lots at me couldn't produce the Ks or Is any more and then the smaller ships started not being produced.
4) Accelerators - these do not work with fleet movement at all; interesting perspective but meh not sure I like them and they do split fleets up badly.
5) Jump Gates - I struggle with these. appreciate this has been part of X for a long time (I've played them all to date and got X: Beyond the Frontier on release!) but I just think the mechanics need improving for big ships.
6) Story line - I'm yet to activate it, can't even remember which start I'm using but to be honest I haven't looked... happy building my fleet and economy... but now I've got 11b credits, a fully fledged couple of sectors that are stable and producing everything I need (I can produce fleets of up to 30 L ships and 1 XL in about 20 minutes now)
7) Fighting - turrets and ships; terrible yet again in sector - turrets can't hit anything and ships do random stuff. Really wish they could improve this somehow but seems fundemental to X4 given at patch 3.1 it doesn't really seem good.
8) Sectors - ok I guess, a decent number but the spacefield doesn't vary dramatically unfortunately.
9) Ships - Odd mix of sizes; no Xenon I equivelent and they all seem a little small for their tiered duties. The carriers suck though; why not use launch tubes like the in the past for rapid deployment/landing and then the pads for drones traders... makes it hard to launch a large scale assualt quickly or recover safely.
I guess this is a proper X game, with all its quirks... its kept me entertained but I'm finding the factions are not really fighting each other, xenon make some incursions but then don't do much depsite them having about 5 Is in adjenct owned sectors that could cause complete chaos to the other factions if they so chose. I think they need to evolve the long distance mechanics soon, the jump gates are startign to become difficult.. X3 was terrible when you met an L/XL ship coming the other way but right now it takes ~5 minutes for a small fleet of 1 XL / 15L to leave a sector! I don't think the lore can move to hyper drive style but it needs to do something different imho.