[crdb]

GA is not "live"; it takes about 1.5 days for the "raw" data (hit level) to be available in BigQuery, and cherry on the cake, they'll charge you extra for the privilege.

I was fond of Webtrekk, which whilst only one day late, cost 1/10th of GA and had a relational schema to their raw data.

If you're going to use your data for something other than watching users click on your site (e.g. using the live data to have the site adapt to the user's actions), you absolutely need to be controlling the DB in which the hits are being recorded.

I haven't had the chance yet but I think only Piwik (or a bespoke tracker) will let you do that. Given a choice, I'd have Piwik write to its own DB, replicate it live, and use that to feed my recommendation algorithms. Bonus: your customer's data doesn't end up on someone else's servers (although in practice, it will, because DoubleClick, Facebook, etc. will all have their tags on your page anyway).