INOUI vs OUIGO Paris to Aix TGV station

Nothing wrong: you cannot pick a specific seat in 2nd class on Inoui trains.
It's still more comfortable than Ouigo.

In a nutshell, Ouigo:
- is often cheaper but not always. The only advantage vs. Inoui!
- has tighter seating with no recline, no middle armrests, and some awful middle seats
- has luggage restrictions
- has a 30-min check-in requirement
- edit: i forgot, no catering!

Thank you Balso for the information. If you could: Is Inoui good about honoring your seat preferences? How early do you have to arrive for Inoui since you do have to get a seat reservation? Thank you for your help.

Ouigo was created to give people with lower budgets access to high speed rail. You get less space and comfort in the chairs on Ouigo than TGV. Also there is no food service on Ouigo like TGV but you can bring your own which is much better than any kind of food served on a TGV . Not sure why you are seeing that you can't select your own seat on TGV. You should be able to select your own seat instead of letting the system default to select it for you.

I'm booked on a TGV Inoui from Paris to Reims and def have a seat selection...?

Hmmm. I am asked for preferences, but no specific seat has been set aside and included in the reservation. You are traveling 1st or second class? I think first class, yes, you can reserve a seat. I will try again. Thank you kindly. :)

@skunklet1771, you were allocated a seat, but unless you are in first class you cannot pick a specific seat. You can, however, request one of various seating plan options.

Thank you. Yes, I'm discovering this is confirmed, so I'm wondering how early one must arrive at station to get actual seat. Is Inoui good about honoring one's preferences?

A lot of the time in second class INOUI, your seat is assigned. You'll see the car and seat number on you ticket when you check out. In first class, you can choose your seat. You don't have to get to the train station early to scramble for a seat; it's assigned when you buy your ticket.

OUIGO has those awful three across seats, little luggage storage. But if you buy a higher-level ticket, you can choose your seat. There are a few single seats. Edit: Some OUIGO cars are 2-2 seating. It will show up on a seat map on the higher-level ticket. The three across are 3 seats--1 seat.

I'm looking right at my app and they gave me a seat assignment for both in and outbound, coach 8, seat 61 on the outbound and coach 8 seat 42 on the return, so yeah, I'd say that's confirmed and reserved.

It most certainly is! lol

Seats are allocated when you buy the ticket. So you say for example you want an upper level window seat, and if possible the reservation system will give you one. Your ticket will show you where your seat is.
So there is no need (nor use) in coming early. You must be on the platform 2 minutes before departure. I would aim to be at the station 15min before departure.

if you watch videos by Thibault on Youtube at Simply Railway, you can see actual train interiors.

I think sometimes they hook up a Ouigo to a "regular" TGV and run them as a combo.