'advice' is uncountable therefore you mustn't add 's' as it's never plural; therefore it becomes "advice is". Who does 'they' refer to? Without context never use the word 'they'. Use the word or words that explain who 'they' are. For example, 'computer engineers'. And don't use the words 'aways' and 'some' in the same context. Always means 100% of the time. 'Some' means more than nothing, but not a lot. 'Some experience' indicates 'they' are not experts. You would never say someone is 'always' reliable or 'good' if they only have 'some experience'. I hope this helps!

Not sure about what you meant by "they have some experience".