Well... several years later I'll post a mini TR.

I've since attacked this route from three directions so have a good feel for it.
This map link describes it. Remember to display the 'terrain' layer in Google Maps.
http://goo.gl/maps/dBYu1" onclick="window.open(this.href);return false;
Due to poor judgement, we followed the wrong set of cairns (there are many) SW from the southernmost unnamed Chain Lake. I was biased by the map from Schifrin's Emigrant book. This was a mistake and killed a day with nasty bushwhacking down a drainage towards Bourland Creek. Once we realized our mistake we went back to the same unnamed lake and camped. We took solace in the margaritas I'd packed in. (1 nalgene of frozen tequila/triple sec + 1 nalgene of frozen fresh squeezed limes/sugar/splash of OJ. Insulate in your sleeping bag so they remain cold). This helped ease the disappointment. (On the return trip the many sets of cairns became apparent, and the Schifrin route map is misleading.)
The next day we actually found a 'different' set of cairns leading E from the lake that basically followed the old mostly non-existent trail on the Schifrin map down to Studhorse Meadow. This wasn't our intent, but we followed it. We then followed the Piute Creek drainage down to the confluence of Cherry Creek. Note to self: this 1+ mile of bushwacking down steep joints + steep drop-offs + much backtracking was HARD and slow going. Next time just take the direct route and drop straight down from Chain Lakes to the confluence, or go over the unnamed pass from Studhorse to Louse Canyon.
Near the Piute/Cherry confluence everything opens up to wide granite and becomes very easy. We followed Cherry Creek steeply up to the 'hanging lake' Plukshin describes, and were grateful the water flow was low. This hanging lake is nice. In fact, the entire route up Cherry Creek/Louse Canyon kicks ass. I did it downstream from the north a few weeks ago.
At this 'hanging lake' on the West Fork you follow the obvious ramp SW up up up to the top of the granite knob and then veer SE into a smaller valley (was unexpected but obvious later when looking at the map) and then up and over to the most awesome view of Hyatt Lake. A long, wide lagubrious granite wall leads down to the lake. If only there was a water slide all the way down...
There were at least three parties already established along the lake when we arrived in 2008 (we were bummed). While it is a great lake, I think its reputation is now outsized and I doubt I'll return. This year we were at Pingree and above Big Lake and saw no one. I'll return to those lakes prior to returning to Hyatt. Pingree can absorb more people due to all of the tree cover.
On the return to Chain Lakes we were certain we didn't want to return up the nasty joint controlled Piute drainage to Studhorse - and we were uncertain about a direct attack up the north wall (as plukshin describes) - so from Hyatt we backtracked to the hanging lake/Louse Canyon and went upstream to an obvious pass that is directly across from Studhorse Meadow. This pass is short, steep and easy. Little evidence of others going this way. From Studhorse we returned to Chain Lakes up the same route we had descended. Of course, once at the top overlooking West Fork Cherry Canyon just south of Chain Lakes, we saw another set of cairns heading straight down the wall to the confluence. Next time.
I've since done the Studhorse/Louse Canyon pass again this summer, while heading south down Louse from Rosasco Lake. This provides an alternate way to get back to the Crabtree Trailhead while avoiding a few miles of trail. It's easy cross country north from Studhorse to the trail.
I've subsequently decided that a good 3-4 night loop route, mostly x-country, is as follows:
Chain Lakes to West Fork Cherry
West Fork up & over to Hyatt Lake
Follow Hyatt Lake Drainage to Cherry Canyon
Southbound Cherry Canyon to confluence of West Fork Cherry
Return upstream West Fork Cherry to Chain Lakes
This would only be easily possible late season when the Cherry crossings are safe. I've done all segments over the years with the exception of the last leg up West Fork to Chain Lakes. I think it's a winner. Thoughts?