How Good Is GPT-5.5 Pro at Summarizing Customer Contracts?

We ran a buy-side deal this summer that included summarizing about 50 of the target’s customer contracts. Because our own homegrown contracts AI isn’t built for summarization, we used GPT-5.5 Pro to do the first pass. GPT-5.5 was the best available OpenAI model at the time we did the review, and “Pro” was its most “think-ey” setting.