I thought that I would offer up an opinion as someone who has used both options to/from CDG....
VEA Navette
http://www.vea.fr/uk/infos-horaires.asp
). Walked me to the bus, where I was last to board. There was only one seat free (and my apologies again to the woman who was kind enough to endure my rather ripe smell after 36 hours of travel from small town India!)
The return trip was uneventful, although we did encounter rush hour traffic. Again, total trip time was about 60 minutes
TGV
www.sncf.fr
However, I also realize that a lot of non-Europeans do not take trains very often. It may be a challenge to navigate all the ins and outs, such as picking up the ticket in the office, validating the ticket at the machine, waiting until the track number is announced about 10 minutes before departure, finding the correct track, determing which letter indicates the assigned car. All of that is pretty much second nature to me, but I did realize last week that it can be very confusing to those who don't take trains very often or at all.
Also, if one lands at anything but T2, it can take time to navigate and take the interterminal shuttle bus.
On arrival at the train station at Marne la Vallee, one will then need to take a bus or walk to the hotel.
Overall opinion: if I am alone, or with another adult, and have little luggage, I will continue to take the train. If I arrive during a slow time, and have more than piece of luggage, I will most likely take the VEA navette.
VEA Navette
http://www.vea.fr/uk/infos-horaires.asp
- 16 euros per adult, 13 euros per child each way
- runs every 30 minutes - 60 minutes throughout the day
- first trip to CDG is quite late ie 730-8am so doesn't work well for early morning flights
- Sunday 12pm left T1 full; headed to T2 and left about 40 very unhappy passengers on the kerb
- total travel time to SL (2nd hotel) was 60 minutes
- had no luggage on the trip there, but on return trip driver was very helpful with luggage

The return trip was uneventful, although we did encounter rush hour traffic. Again, total trip time was about 60 minutes
TGV
www.sncf.fr
- leaves from train station at T2 so if arriving at another terminal you will need to get to T2 train station; this can be a little challenging with kids or lots of luggage
- fare ranges from about 14,90 euros to 25,00 euros depending on time of day/date
- train runs every 45 minutes to 85 minutes on average, with earlier starts than VEA (but still not always early enough for those with 8am etc flights)
- total trip time 10 minutes
- can be booked in advance ie a guaranteed seat
However, I also realize that a lot of non-Europeans do not take trains very often. It may be a challenge to navigate all the ins and outs, such as picking up the ticket in the office, validating the ticket at the machine, waiting until the track number is announced about 10 minutes before departure, finding the correct track, determing which letter indicates the assigned car. All of that is pretty much second nature to me, but I did realize last week that it can be very confusing to those who don't take trains very often or at all.
Also, if one lands at anything but T2, it can take time to navigate and take the interterminal shuttle bus.
On arrival at the train station at Marne la Vallee, one will then need to take a bus or walk to the hotel.
Overall opinion: if I am alone, or with another adult, and have little luggage, I will continue to take the train. If I arrive during a slow time, and have more than piece of luggage, I will most likely take the VEA navette.