Load Balancing Software Resources

I've been researching what enterprise load balancing platforms have the best support for zero-downtime deployments so engineering teams can push updates without customer-facing interruptions. It's one of those requirements that most tools list as supported, and I wanted to dig into what the real-world experience actually looks like across different options. Curious what people here have found.

Here's what I've been looking at, with ratings for reference:

• HAProxy (4.7 stars, 900+ reviews): Zero-downtime reloads were the standout in enterprise reviews; routing traffic away from a backend before it restarts was the main reason teams chose it for deployment-heavy environments.
• F5 NGINX (4.6 stars, 107+ reviews): Shows up frequently in microservices setups with rolling updates. Low memory footprint means it doesn't compete with application resources during a release.
• F5 BIG-IP Local Traffic Manager (LTM) (4.5 stars, 40+ reviews): Built for enterprise traffic management with connection draining and iRules for custom routing logic during deployments. Reviews from large enterprise teams cite it for coordinating traffic shifts across complex multi-tier application stacks.
• Progress Kemp LoadMaster (4.7 stars, 213+ reviews): Ease of configuration and built-in health templates for release visibility were the most cited reasons teams chose it over alternatives.
• AWS Elastic Load Balancing (4.5 stars, 95+ reviews): Graceful draining with configurable deregistration delay is the feature most cited for zero-downtime deployments. Auto Scaling integration means new instances come online before old ones are removed.

For teams pushing multiple releases per week, which of these has the lowest operational overhead during an actual deployment? I'm particularly curious whether anyone has measured how long the traffic drain takes before a backend can safely restart. And has anyone run into a case where the drain period itself became the bottleneck and ended up slowing release velocity more than expected?

Which load balancing platforms have the clearest pricing and no surprise per-request or bandwidth overage charges for a company that has been burned by unpredictable costs before? I've been researching this after seeing it come up repeatedly in cost discussions; the billing model is often the thing teams regret most, not the tool itself. I wanted to get the community's take, so sharing what the reviews say and curious what people here have actually experienced.

• HAProxy: free to self-host, no usage-based charges at all; you own the operational overhead but the billing is as predictable as it gets
• Traefik: open source with SSL, rate limiting, and auth middleware included; no per-connection fees, pay only for the infrastructure
• Progress Kemp LoadMaster: flat licensing cost, not usage-based; reviews called it "well priced" and "best value in the market" compared to alternatives
• F5 NGINX: open source base is free, but the Plus edition is also available; adds up fast in multi-server deployments
• Azure Application Gateway: combination of fixed and variable billing components makes it harder to predict month to month

What pricing model has actually worked out cleanest at scale? Curious whether anyone has found a managed option that stays predictable long-term, or whether open-source is always the safer bet for cost certainty.

Which load balancing platforms have the clearest pricing and no surprise per-request or bandwidth overage charges for a company that has been burned by unpredictable costs before? I've been researching this after seeing it come up repeatedly in cost discussions; the billing model is often the thing teams regret most, not the tool itself. I wanted to get the community's take, so sharing what the reviews say and curious what people here have actually experienced.

• HAProxy: free to self-host, no usage-based charges at all; you own the operational overhead but the billing is as predictable as it gets
• Traefik: open source with SSL, rate limiting, and auth middleware included; no per-connection fees, pay only for the infrastructure
• Progress Kemp LoadMaster: flat licensing cost, not usage-based; reviews called it "well priced" and "best value in the market" compared to alternatives
• F5 NGINX: open source base is free, but the Plus edition is also available; adds up fast in multi-server deployments
• Azure Application Gateway: combination of fixed and variable billing components makes it harder to predict month to month

What pricing model has actually worked out cleanest at scale? Curious whether anyone has found a managed option that stays predictable long-term, or whether open-source is always the safer bet for cost certainty.