Family of four arriving at CDG around 1 pm on a Saturday. Taxi or train to our apartment in the 2nd? About how much can we expect to pay vs. taking train/shuttle? Is there a central taxi stand/company that we should be looking for?

For four people, a taxi will be only marginally more than the train and a great deal easier.

Train/métro - 9.75€ each
taxi - 50€ to 55€. There will be a 3€ charge above the metered far for the 4th person and 1€ for the second and subsequent bag placed into the trunk.

Do not accept offers from clandestine drivers soliciting from within the terminals, proceed directly to the taxi queues usually just steps from the Customs exits. Taxi drivers are not tipped, I just round up the fare to the nearest 5€.

Shuttles are notoriously unreliable in Paris and will generally cost more than taxis.

I do tip taxi drivers, particularly if they help with luggage at the dropoff, but no more than 10%.

And, many taxis are now SUV-size so no problem for four people and luggage. Dispatcher will flag over the size you need, no difference in cost.

The bigger question for me is the amount of luggage you will have. If you have smaller, manageable luggage, I'd say take the train, it will likely be quicker. If you have more than one bag per person, take the cab.

If you have an internet access on your smartphone, I recommend you look at the traffic situation by firing up google map and turn on traffic especially on highway A1 connecting CDG and Paris. You should not have too much problem in general at that time, but generality does not help you in reality. What counts is what is the situation at the time of your arrival. You don't want to get caught in unexpected delays like this one: http://online.wsj.com/articles/photo...ike-1402495206

The traffic app will give a hint that you might get stuck on highway irrespective of the cause.

Research the RER train route, including how to pay for the tickets, in case you have to use it as a fall back.

Be aware the RER is affected by the train strike. Met a couple last night who were dumped off the train short of their hotel destination. They were novices to Paris and the trains and felt stranded.

The CDG trains were only going to Gare du Nord. Not exactly being stranded but it could be disorienting. One of the many reasons why I always strongly suggest to those visiting Paris for the first time to take a taxi.

Taxi, hands down. Just walk out to the taxi queue at the curb, hop in one that can accommodate your party (as noted, minivans are increasingly common) and go on your way. The slight difference in cost between taxi and train will be more than compensated by the convenient and comfort of your group.

To go to the 2nd, the Roissybus might be your easiest option. It all depends on the exact address.

http://www.ratp.fr/fr/ratp/c_20579/roissybus/