Seems you’re asking different things.
Despite being experienced with TQ I waited a long while before picking up GD as I[ul]
[li]had little faith in Kickstarter;[/li]
[li]wanted to make sure the project could actually wind up going somewhere.[/li]
[/ul]
So no, TQ did not sell me on GD. That’s entirely GD’s doing. TQ definitely made me start paying attention, though.
I enjoyed the game quite a lot actually, but i got bored around my third character. The overall area design was rather bland, specially with every cave looking the same. And Egypt is probably the worst with it just being one giant desert with very few things in between. I know Egypt is much more than one giant desert.
Not to mention the plot was really bland and completely uninteresting. Stop the big bad guy, the end. Really boring. At least Act 4 improved everything and i’d argue that is better than all the previous acts combined with much better area design and story.
I also got dissapointed when i found out there was no act for Norse mythology.
Grim Dawn pretty much improved everything with much better lore, plot, area design and combat. Honestly, it made Titan Quest obsolete. I honestly just play TQ for 15 minutes before i just decide to just play Grim Dawn.
Not to mention that not being able to put components in epics and legendaries is probably the worst design decision in the game and thankfully they wised up in Grim Dawn.
While I only played it once at the time, I did love TQ back in the day. But now, after playing GD, TQ just seems kinda…awful. It has its plus points, sure, but having played through the Anniversary Edition recently I can’t help but feel like a lot of my love for it over the years might have been down to the pair of rose-tinted glasses I’ve apparently been wearing this entire time. In my mind, the environments were huge, detailed and fun to explore, but in reality it’s just this endless blur of fieldforestfieldforestfieldforestfieldforest, occasionally spiced up with an identikit cave or two. Granted, the Immortal Throne content was an improvement, but sadly that didn’t save the remaining 3/4 of the game that came before it. :undecided:
The gameplay also feels really slow and uninteresting (even using Anniversary Edition’s new game speed feature), but perhaps I’ve just been spoiled by GD’s slew of Devotions and item abilities. Leveling up seems to take foreeeeeeever too.
But yeah, GD probably just ruined it for me. I liked TQ at the time and I guess that’s what counts, I suppose. 
D2 was and will be the #1 ARPG in me till I die…
I discovered TQ after D2 became stale and I immediately fall in love with it (still love and play Soulvizier to this day). The mythology lore, the monster specific itemization and the very many class combinations are unique in this genre and the reasons I loved TQ. There are some glaring flaws but if Ironlore didn’t close down, perhaps they could further improve with patches… (one can hope)
I bought GD in a heartbeat because of TQ. Personally, I am a bit disappointed that GD turns into a proc machine with vastly proc centered devotion and item designs. I want my Commando to be a Commando, i.e. Flashbang, throw some grenades, shoot and Blitz. Not calling down meteors, spewing molten rocks, shooting fire trails, walls, rings and rainbows… covering the whole screen in flame by pressing 3 keys. TQ was more to the root and not too flashy.
I still like GD though, but not to the extend of my love to TQ (Soulvizier).
P.S. I’ve seen so many ppl complaint about the game speed in TQ. I agree early game is painful, but by end-game Prophet with 300% cast speed and 166% movement will blow any casters in GD out of the water even without significant cooldown reduction.
TQ is why I joined the GD KS.
i liked T when it 1st trailer came out, it was so dam epic :D! then i played the demo, i was sold, i loved the graphics , the skills, the classic greek music and the mobs!
i still playing today, mostly the LOC mod 
Yes, TQ was the reason I got GD. The dual-class combo thingy is genius!!
I contributed to the Kickstarter back in '13 - I thought this looked like the spiritual successor to TQ/D2, both of which I played for years. I followed the development all those years and I was not disappointed! Never thought I would see a game like this again with all the FPS and mobile games now.
I distinctly recall reading a Rock, Paper, Shotgun article saying that the TQ devs had a KS for another ARPG and i was instantly sold before even viewing the campaign. After seeing the video I knew I had to have the early access tier to get my hands on it ASAP. I didn’t pay for the expansion tier only because money was a little tighter back then, but I really wanted to.