As for whether or not it is worth it. Opinion/answers will vary. To some it is without question. To others who have enjoyed very nice offsite stays and then splurge they wonder why they did since they always enjoyed their offsite stays just fine for half the cost.
We have stayed onsite more than we have offsite. But I can tell you that those offsite trips were still very fun and while we did miss the magic of staying onsite, it didn't affect the trip. Sometimes if I can't get good airfare or don't have ff tickets, I just can't swing it. And last minute deals at the three onsite hotels are hard to come by. They almost always sell out on the weekends so they don't need to offer much in the way of great deals.
If you can afford to stay onsite without cutting back on other things you want to do such as nice sitdown/character meals, souveneirs or the length of your stay, then go for it! Its a lot of fun and you'll be immersed in the magic. If however staying onsite is going to be a burden then by all means stay offsite and have a marvelous time at
Disneyland.
And as for the distance to the DLH. I have stayed there with kids as young as two and while its not a short walk its a pleasant one up Downtown Disney. My kids and my nieces always got so distracted with all the shops and entertainment surrounding them they didn't mind it too much. And there is the monorail to fall back on as well. And onsite hotel guests get priority boarding for the trip back from Tomorrowland. If you do walk it, I would say from the turnstiles of Disneyland/DCA to the hotel is about 10-15 minutes depending on how fast you walk.
And as far as standard views, that can be anything from a parking lot, to a view of the Koi ponds to one of the lower rooms in the Sierra Tower facing DTD. I once got a second floor Sierra Tower/DTD side that was actually nice since some palm trees were right outside there. We could even see some of the fireworks even though we were so low. Another standard view I had in the Bonita Tower had a view of the fountains, the wedding pavillion and the Matterhorn. But I also got stuck with a parking lot view once which wasn't the end of the world but definitely very "standard"!