Funny you should ask, I was in DLP right around this time last year. We checked in on the 22nd and out on the 27th (5 nights all on points).
Weather-wise it was a good time to go. It was DEAD in the parks during the week, but when we checked out on Saturday there were crowds of people coming in from the train station as we left.
IMHO I wasn't really impressed with DLP. I loved Paris, but not DLP.
This was my impression as well - I was there for one day in March. I'm glad I went for the experience, but I would take time away from Paris again for it.
Both parks and downtown Disney are within walking distance from most of the hotels, so if you can use the points elsewhere I would.
The next time I go to France I would stay in Paris and take the train to Disney. It is very convenient and about 40 minutes from Paris.
It really is convenient by train - the train station is right outside Disney Village (I was shocked at how close it was when I got off the train).
We flew into CDG and took the VEA bus to Disney (it's like the buses that you can take from Orlando to WDW). They were easy to use and I think it was a good choice.
I flew into CDG and took the TGV from there. You can buy one-way or round-trip tickets from the TGV office at the airport train station. You'll want to take the TGV going in the direction of Marne la Vallee. I think the trip was about 12 minutes, but I actually went to Val d'Europe, which is the stop just before Marne la Vallee. Looking back, it was really easy to do, but I do a lot of traveling and learned enough French (still very little) to be able to ask questions. The train station is big and the signage is not terribly clear. I figured it out after talking to someone who spoke no English, but I wasn't really convinced I was on the right train until I got there.
I didn't use points for the trip - I stayed at the
Elysee Val d'Europe Hotel, which was basically like an Econo Lodge but very nice on the outside and in a very safe area. VERY basic rooms though - but CHEAP - $75 US for the night. The advantage was that it's the only offsite hotel that offers early entry to the parks. The train station is right across the street from the hotel, and the RER line to Marne la Vallee is quick - a couple of minutes. The hotel is in a little shopping district and adjacent to an outlet mall.
The RER line is the best way to get back to Paris. Just don't fall asleep and miss your stop.

I ended up at the Charles de Gaulle station, which is not to be confused with the airport station - this one is at the Arc de Triomphe. That was not really a bad way to arrive in Paris - off the train and rise from the station level by escalator and have the Arc be the first thing you see. Sweet.
They do offer tours, but the train was so convenient that we just did our own thing.
Yes, pretty much all the hotels offer Paris tours through the concierge, but with a little planning you can easily go without them. (Unless you are very worried about being on your own.) Something very easy to do is book one of the on-and-off day passes for city bus tours. This can be bought online and you'll get a voucher to print - you can get on and off the bus at any of the tour stops all day long.
That said, the Paris Metro is ridiculously easy. I speak very little French (but apparently dress like a Parisian because I was mistaken for one by other Parisians constantly!) but I had no trouble getting around.
On the plus side, their Space Mountain kicks WDW's butt by a mile (it goes upside down like the Rockin Rollercoaster) and the Crush Coaster in the Studios park is a really great ride. I wish they had one in Florida.
I totally agree with Space Mountain - the themeing outside is great, but inside it's a little blah. Just a few random pictures of galactic objects (Hubble shots). The launch is awesome and the ride is so much smoother. I'm hoping the revamped Space at WDW is that smooth!
I didn't ride Crush because pretty much all the FP machines weren't working.
I thought most of the rides were pretty similar. BTMRR is longer and has longer dark portions. The Indy coaster was okay- nothing great. It was neat to see the different Haunted Mansion (Phantom Manor) but it wasn't as good as WDW IMO.
My overall observation is that DLP is missing the richness of detail of WDW. It's nice and there are cool things, but if I would travel to Europe just for that. JMO.