Update index.md

Author: wslyvh

src/content/developers/docs/networks/index.md

@@ -39,9 +39,17 @@ The two public proof-of-stake testnets (which client developers are maintaining
 **[Sepolia](#sepolia) is the recommended default testnet for application development**.
 The Sepolia network uses a permissioned validator set. It's fairly new, meaning its state and history are both quite small. This means the network is quick to sync to and that running a node on it requires less storage. This is useful for users who want to quickly spin up a node and interact with the network directly.
 
+- Closed validator set, controlled by client & testing teams
+- New testnet, less applications deployed than other testnets 
+- Fast to sync and running a node requires minimal disk space
+
 **[Goerli](#goerli) is the recommended default testnet for testing of validating and staking**. 
 The Goerli network is open for users wanting to run a testnet validator. Stakers wanting to test protocol upgrades before they are deployed to mainnet should therefore use Goerli.
 
+- Open validator set, stakers can test network upgrades
+- Large state, useful for testing complex smart contract interactions 
+- Longer to sync and requires more storage to run a node
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 #### Sepolia {#sepolia}
 
 Sepolia is a proof-of-stake testnet, and is the recommended default testnet for application development.