I couldn't believe Trattoria would attract such uniformly negative, off the mark reviews so here's a counterbalancing opinion. Not to suggest the two reviewers of record here didn't have a bad time - clearly they didn't enjoy their visits. Nevertheless as a long time Whistler resident, not connected in any way to the industry (except as as regular customer of most of the restaurants in town) I can attest that this is one of the benchmark restaurants in this resort town, and I have eaten there with great pleasure probably over a hundred times - sometimes two of us, sometimes our whole family, sometimes as part of a bigger group. Its always a good experience. That's why we go back.
A trattoria is by design noisy, informal, with a straightforward menu. The name should tell you what to expect. This is not a place with hushed atmosphere, cutting edge cuisine, and reverent service. At dinner, the place is always jammed, always noisy, with lots of large parties having fun. The room is warm, the kitchen is open and working, and the wait staff are necessarily efficient. If you want a quieter, more intimate experience I can highly recommend lunch. Its one of the best mid-day spots Whistler has to offer. Get a table by the windows, order a nice bottle of wine, and relax watching the snow falling onto the silly tourists in the outdoor pool. The kitchen is busy prepping for the evening rush but the staff have a lot more time to relax and chat.
Obviously the Tratt delivers what the public want, because its one of the most successful, long-standing places in town. Like most Whistler restaurants the staff are often young and transient, but I have always been professionally served by friendly and knowledgeable people. A great wine list (for a ski resort trattoria) complements the limited, but excellent, food menu and staff will capably recommend good selections at all price levels. Umberto's own wines are a reliable choice and deliver good value.
We're talking Whistler after all so the final bill isn't going to be "cheap" - but on a relative basis, value for money is better here than in many other places. So go with your eyes open, relax and enjoy what the Tratt has to offer. No, its not Wildflower or 5280. Thank goodness.