I think that it is wonderful that you are going to give
Disneyland a go, it is a wonderful place and has special charms about it none of the other Disney parks have!
Can you tell I am biased?
First off, yes DL is smaller, but for me, I find it much more convenient. Everything in the 2 parks are much more manageable and quicker to get to. There is just a big courtyard or espalande separating the two.
I am usually different than most people, because I love taking a long time at Disneyland. We usually go about 5 days, but we love to see all the shows and fireworks, and have plenty of time to just stop and enjoy the atmosphere when we want, and take breaks during the middle of the day. I have a friend that goes for 7, but during the busy time of summer...
Most people prefer 2 to 3 days, and say that it can be done, but would be some pretty packed touring days. I think it would depend on how many days you prefer at WDW, and if you like breaks during the day or not. Go with whatever is best for your family.
And a key difference in the places that you can stay, is at DL everything (especially offsite hotels) are so much CLOSER. It is so refreshing to me to be able to stay close enough to walk to the parks every day. At WDW, you may be close to one park, but have to take transportation to the other parks. Disneyland has 3 onsite hotels: The Disneyland Hotel, the Paradise Pier Hotel, and the Grand Californian.
Best Western Park Place Inn and the Best Western Parkvue Inn are the closest hotels offsite, and are right across the street and offer great rates. Alot of people prefer to save money and stay offsite because it is so convenient to the parks (unlike WDW). I mostly stay onsite, but have stayed offsite a time or two. I would suggest to get a hotel within walking distance, and not one with a shuttle...much more flexible that way.
HTH!