I know... I know. Even mentioning this game could make some bad memories resurface for you guys but guess what? I'll risk it
I bought it a few weeks ago and been playing a lot since then. I don't know how bad it was at start (I heard many opinions but haven't tried it myself since now), but I can say that now it's in a really good state. There are still many many quirks and frustrations but there are mods that fix those and the base game is getting updated all the time too. 2.5 patch was the last big one and it was the point when many players returned to the game. Some people still dislike the focus on "smaller" empires when compared to the X3 but if you look at it like a different game, I have to admit it is at least fun. I got 50 hours out of it without even bothering much with empire building, if they ever work on that (and I'm sure they will, or at least the modders will) I expect to have more hours on this than X3:TC and AP combined.
There's also the 3.0 patch due early December. There's an early preview in the beta channel but the changelog is going to increase by then (many great changes and crucial bugfixes already confirmed by the devs). Notable changes are: the way the map works (seamlessly zooms in and out, you're able to move and rotate it), economy rebalancing (base price and discount update), inventory item crafting (not much known at this point). 2.5 added X3-like sidebar menu instead of the hated circular menu, external camera, free look in cockpit and shipyards for small and medium ships.
So, if you own the game - I'd recommend you give it a try again now. I finished the main plot, took me around 40 hours and I'm now working on stations and fleets. I gotta admit this part is not really fleshed out, the fleet management is minimal at least but at least individual ship commands are getting better and better. Stations are very time consuming to build and manage but with small tweaks to the benefits of owning one it would be justified - I kinda disliked how easy it was to build stations in X3 (although I miss the manual module placement and linking, even if it did look like spaghetti in the end).
Not much of a review, I know. I just wanted to remind you that the game still exists and is being worked on, there are some great updates incoming and the game is really becoming better and better. If you might be interested in an space adventure game, this might be for you. Check out my screenshot gallery on Steam to see how the game looks (it's beautiful), there have been many performance optimizations since start if you're worried about that (and more are coming in the 3.0 patch). If you do start playing, I'd really recommend you start installing mods as soon as possible. The Steam workshop for X:R has saved the game for me, there are some really frustrating things in the base game that these mods remove (like minitalk requirements for viewing crew skills and recruiting trade agents, constant audio confirmations when trading stuff, diminutive station scan range, mining AI,...). Check my favorite mods if you're interested in that (although pretty much "any mod being updated on Steam Workshop" is my favorite at the moment).
Important notice: the game is going to get a DLC soon, called The Teladi Outpost. The DLC is FREE for all current owners of X:Rebirth, but isn't automatically added to your account - you need to go to the store page (linked above) and claim it soon. The deadline was technically until 1.11.2014. but it's still available so, no reason why you shouldn't take it if you bought the game already.