Personally I agree with the OP. Having played EE before the original, now I realize how different the EEs feel compared to the true games.

Baldur's Gate feels extremely comfy from the start. I believe the UI has a lot to do with that, since it's an UI that aesthetically matches the rest of the game, whereas the EE's UI feels way out of place (same happens with the cutscenes).

But don't get me wrong. I think the EEs have introduced a huge amount of quality of life improvements, with the most important ones (IMO) being the ability to zoom in and out, which is great when you want to see exactly where everything is or you just want to appreciate the scenery without an awful resolution, and the various changes to the UI in the inventory and character screen, which makes for easier reviewing of your stats and equipment.

If I could ask for something else from the Enhanced Edition, it would probably be that the UI more closely resembles the original since I find it to be very pretty and pleasing with the engraved-on-stone look of the icons.

The original Baldur's Gate is still the best "edition" in my opinion. I play it to this day and there's nothing wring with it. I personally hate the BG2 engine and all that comes with it. It messes up the balance, makes the game easier and simply looks ugly. When I first heard about EE I was so happy that the game will be updated and have more content. The more I knew about it, the more disappointing it became. Still, I played it untill reaching Baldur's Gate city and lost all the hope in Beamdog. Going back to the original felt so great. To me EE is just a different game and I'm a bit glad the new expansion failed.

It may be nostalgia, but for me in the original everything fits together: character animations, slow walking speed, no pause in inventory, cutscenes, stone UI and so on. Nowadays most articles about Baldur's Gate (especially about its legacy and history) have screenshots from EE, which in my opinion should not be the case. It makes me sad that GoG soon will merge the original with EE.

Yes. It is better for quite a few reasons.

1) Weapon proficiency system. The ones in Original 1 were really great, awesome. Even better than 2's...

2) The rules weren't identical to 2's. This had quite a few nice little perks:
a) Summoned creatures were MANY in number, not 1-2 per spell.
b) Classes. You weren't forced to choose a kit from 1, you did that in 2. Also, certain restrictions weren't in effect.
c) Mage specialists. 1 had quite a few more liberties in rules than 2 (i don't remember the details right now, though).
d) Same as the above, but regarding dual class options.

3) 1 felt like another game with its different rules. It wasn't exactly like 2 and yes, this system had quite a few benefits to the player (should you bother to search for, or identify them, while on the go).

I am sure there were many more differences, but it is a really long time since i played through this series, i am afraid. Also, i didn't like the EEs (especially for them defying lore and allowing class combos that weren't available in the originals, among other things) and didn't play through them, to notice and list ALL differences between them. Lately too, i also REFUNDED ALL BEAMDOG titles, to actively show my dissatisfaction with the degradation of this all-times-classic-game the new DLC content and liberties of the EEs brought to the table. I prefer the originals in each and every aspect; plus, i wouldn't like for them to merge in my game shelf. Originals have a special place. The new garbage content can go die, for all i care.