The exact details are a little fuzzy but as I recall, veteran single hand sailor Skip Allen was testing both the Simrad TP10 and Raymarine ST1000 tiller pilots for Practical Sailor during a recent Singlehanded Transpac on Wildflower, the modified Wylie 27 he built in 1975. Both pilots worked well. but I think the Raymarine got the most use during the crossings. Unfortunately, he had to scuttle his modified Wylie 27 only 250 miles from San Francisco as he was returning from Hawaii. Apparently, the pilot was still functional despite 30 mph winds and 15-30 ft seas as the boat disappeared from sight.
Suggest you get a copy of the tiller pilot review in the June 2009 issue of Practical Sailor from their website to get more details. Both of the units reviewed are entry level models designed for moderate sea conditions for boats 30 ft and under; however, it is apparent from the Allen test, they are capable of handling more severe conditions when required.