I have stayed there twice. The room is facing the ocean and the view is beautiful and relax. The room is not new but clean and nicely decorated. I had tried both breakfast and lunch at the cafe there. The breakfast has a long of variety, you can make your own bowl of raw tuna and scallop with rice. Lunch buffet is comparatively basic. It is connected to a big shopping mall and supermarket. It is not at the city center but there are bus and train nearby.

Full service hotel with grand lobby. Excellent buffet breakfast with extensive Japanese choices, including make-your-own sashimi chirashi don. Hotel attached to huge shopping complex. However it is not located in the canal district, or within walking distance. LAN internet only. Tight underground parking.

Grand Park Otaru was the first hotel we stayed in when we landed in japan, and it was by far the biggest and most comfortable, with a king-sized bed, full-sized bathroom and comfortable sitting area. We booked the cheapest room, which gave us a view of the mountains and the town, but I think more money would buy you a nice view of the sea. From Chitose Airport, we took a train to Otaru-Chikku station. From the station, it was about a 7-10 minute walk to the hotel, but a pleasant one (for a shopaholic like me), as you walk through the Wingbay shopping mall, that leads to the hotel's 2nd floor. Even with our luggage and suitcases, we didn't feel the distance was a problem. But if you arrive at night when the mall is closed, you will have to take the outdoor route to the hotel, which could possibly involve some stairs.
The mall has a large 100-yen shop & a huge hardware store. We didn't book the breakfast, but there's a good Aeon supermarket that's directly linked to the hotel lobby, so we bought bread, milk (the milk in hokkaido is fantastic - try it!) and cheese, and had a very pleasant breakfast in our rooms. The size of the Grand Park Otaru room is a huge plus in Japan where hotel rooms are generally miniscule, so enjoy it while you're there! The staff were helpful and spoke reasonably good English.
A 10-minute walk away from the hotel is a large 2-storey recycle shop by the Hard-Off group. They sell 2nd-hand clothes, books, games, clothes, bags, shoes, household items. Just loads of things in general - it was just a pity we didn't have enough time to trawl through everything. It is about a 20-30 minute walk from the hotel to Otaru Canal. There's a public bus that brings you to and fro for 210 yen/way. The bus stop is right in front of the hotel where the revolving door is. But if you have a group of 4, it probably makes more sense to take a cab. We took a cab from the canal back to Grand Park Otaru, and it cost us 840 yen, exactly what a bus ride for 4 of us would have cost - except that we were back in 5 minutes!
For a cheap meal, check out the little food court in Wingbay Mall, right where MOS burger is. There are bentos from 360 yen, udon from 280 yen and assorted tempura from 105 yen (the tempura crab claw is fantastic value). You can buy your food from any of the stalls and sit in the common seating area which has seaviews.
I'd highly recommend Grand Park Otaru, because of its spacious comfortable rooms and nice staff. Its location is quiet and scenic without being boring, plus it's really close to the train station and mall. If you don't need to be smack next to Otaru Canal, this would be a great hotel to stay in.