Sea to Summit Spark
$$$ Flagship$349.00
tldr; Reddit has mixed feelings about the Sea to Summit Spark; while praised for its industry-leading weight and roominess in Pro versions, some find the Spark 45 too tight or the Pro unsuitable for side sleepers.
$349.00 on AmazonSentiment Breakdown
55%Positive
Positive
55%Neutral
42%Negative
3%Based on 40 Reddit opinions
Strengths & Weaknesses
Each axis shows what % of Reddit comments are positive about that topic. Higher = more praise.
Key Features
- 45-degree Fahrenheit (7-degree Celsius) ultralight down sleeping bag for warm weather backpacking, bike packing, and touring
- High-loft 850+ fill power down insulation (Responsible Down Standard certified) with a non-PFC Ultra-Dry down treatment to improve reaction to moisture, retaining loft and performance
- Ultralight 10D shell with PFC-free DWR keeps the hood and footbox highly water resistant; breathable 10D nylon liner provides all-night comfort
- Contoured mummy shape provides adequate room for a natural sleeping position; YKK #5 zippers provide reliable, snag-free operation
- Baffle construction is sewn through for lighter weight; Sea to Summit Guarantee is offered for the Lifetime of this product
- ⚖️ Industry leading in weight
- 📐 Spark Pro is very wide and roomy for side
- 🎯 Spark Pro is fully zippered and has higher CUIN
Sentiment Over Time
Historical Price Data
Sea to Summit Spark
Sea to Summit Spark
All-time low: $261.69(2024-11)
What Redditors Actually Say
What Redditors Say
Best praise vs top criticism for Sea to Summit Spark
Best Praise
+5 pts“Part of the appeal of the Spark/Flame is the goal to be extremely light, that's why they use the thin shell fabrics, light zippers etc.. You can get beefier models from StS and many other manufacturers. I've been happy with my last gen Spark III and IV.”
r/Ultralight
ViewTop Criticism
+2 pts“If you can order some bags together and compare loft, I was thoroughly unimpressed with the Spark, compared it to three other bags, Cumulus Panyam 450 and Xlite 400, and ended up choosing a Western Mountaineering Megalite.”
r/Ultralight
View9 more quotes available below
Related Products
Frequently Asked Questions
Is the Sea to Summit Spark worth buying?
Reddit has mixed feelings about the Sea to Summit Spark; while praised for its industry-leading weight and roominess in Pro versions, some find the Spark 45 too tight or the Pro unsuitable for side sleepers.
What do Redditors love about the Sea to Summit Spark?
Redditors highlight: ⚖️ Industry leading in weight. 📐 Spark Pro is very wide and roomy for side. 🎯 Spark Pro is fully zippered and has higher CUIN.
What are the downsides of the Sea to Summit Spark?
Some criticisms include: "If you can order some bags together and compare loft, I was thoroughly unimpressed with the Spark, compared it to three other bags, Cumulus Panyam 450 and Xlite 400, and ended up choosing a Western..."
How accurate are these ratings?
Our sentiment analysis is approximately 80-85% accurate compared to manual review. Products with more mentions (Sea to Summit Spark has 40) tend to have more reliable scores.
40 Reddit opinions analyzed • Last updated 5/26/2026