Gemini 2.5 Pro vs Qwen3.5 397B

Pick Gemini 2.5 Pro if you want the stronger benchmark profile. Qwen3.5 397B only becomes the better choice if knowledge is the priority or you want the cheaper token bill.

Gemini 2.5 Pro finishes one point ahead on BenchLM's provisional leaderboard, 64 to 63. That is enough to call, but not enough to treat as a blowout. This matchup comes down to a few meaningful edges rather than one model dominating the board.

Gemini 2.5 Pro's sharpest advantage is in coding, where it averages 63.8 against 60.3. The single biggest benchmark swing on the page is SWE-bench Verified, 63.8% to 76.2%. Qwen3.5 397B does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

Gemini 2.5 Pro is also the more expensive model on tokens at $1.25 input / $10.00 output per 1M tokens, versus $0.60 input / $3.60 output per 1M tokens for Qwen3.5 397B. That is roughly 2.8x on output cost alone. Gemini 2.5 Pro gives you the larger context window at 1M, compared with 128K for Qwen3.5 397B.