While I suppose these routes go, it's worth noting that Gilpin's north ridge offers the easiest climbing route. This ridge starts at the saddle just south of Blue Lake Pass at 12,940' and you can easily climb to this saddle on grassy slopes. From the saddle, follow the ridge south along a climber's trail and avoid all of the ridge's difficulties by staying left (east) of the ridge line. This ridge has a ton of small loose rock and involves class 2+ climbing. This route is harder than other class 2 routes because of the loose rock's nastiness. Nonetheless, it's nothing technically hard and only more frustrating than anything else. Wearing gloves may be beneficial for those times you use your hands for balance. At 13,500', the ridge gives way to Gilpin's accommodating southwest slopes. Early in the season, you will cross a cornice (or what's left of it) that forms in the broad couloir adjacent to the ridge before gaining access to the southwest slopes. This weekend, crossing the snow was relatively simple. From 13,500', it's easy walking to the summit -- just don't trip and fall down Gilpin's northeast face.
I suspect Garratt & Martin don't describe this route because they feel you should climb Emma and Gilpin in one day, and using the north ridge is time prohibitive in this case. However, if you do use Garratt & Martin's ascent route, you might consider this route to descend, especially if the weather is moving in.
P.S. Has anybody done G&M's Gilpin route? What class is it?