1. Performance & Utility – Flash models are praised for speed, coding ability, and competitive quality
“If they can keep up this cadence of Flash leap‑frogging the previous Pro, we’re in for a good time” – swiftcoder
“DeepSeek Flash produces better quality than Gemini does… fraction of the task price” – pimeys
2. Pricing & Cost Reductions – Users highlight the new off‑peak pricing as a major advantage
“Input cache hits (per 1M tokens) – $0.003 Vs. $0.022 Vs. $0.007 … Output … $0.6 Vs. $1.98 Vs. $0.66 … V4.1 Flash is cheaper than the current 0731 flash model” – KyleTheDev
“Current flash prices are 0.66 for output, this is dropping it to 0.60” – aavaa
3. Consistency & Language Issues – Reports of the model switching languages, hallucinations, and nondeterministic behavior
“I finally uninstalled the app yesterday … I asked it whether «DeepSeek has fixed the issue where it erroneously answers in Chinese?» and it answered in Chinese” – gentlewater
“The web UI chat version of flash has very poor language following abilities… sometimes asking something in English… I got an answer in German” – jiehong
4. Model Routing / Version Change Concerns – Automatic routing of Pro requests to Flash raises worries for production workflows
“Please don't do this kind of thing. If a user has validated a workflow on V4 Pro, they might not want to suddenly start testing it in production on V4.1 Flash” – aftbit
“If I'd carefully tested and optimized prompts against Pro I wouldn't be keen on this particular news” – simonw