Decision nightmare: enterprise e-commerce analytics

I am trying to figure out the best-suited analytics tool for a $500m/year e-commerce platform (web & mobile).

Everyone I ask tells me something else and I am hoping to filter some of that noise by posting here.

The most important things for us are:

(i) must play well with both Tealium and Google Tag Manager. We currently use the former but I want to run the later as well to see if we can eventually switch.

(ii) must work across web & mobile (comes with SDKs for both Android and iOS)

(iii) accurate attribution, funnels, etc. I am especially confused when it comes to aliasing, i.e. matching an identity to a user before they log in. Apparently, only Kissmetrics can do that, which I find odd.

(iv) I’d like to implement Segment and also potentially Autopilot, so we can add functionality through third-parties that is not native. This means we don’t need a tool with kitchen sink features and would connect notifications, email, heatmaps, A/B, etc.

(v) Other than that, we care about everything that would matter for any multi-platform e-commerce. Attribution is a big issue, of course, as are accurate funnels, drilldowns, etc.

I am looking at Heap, Amplitude, Mixpanel, Pendo, Kissmetrics. We’ve already ruled Firebase out. I also started to look at Oribi and Roivenue, but have not talked to them yet.

I’d be grateful for any first-hand experience with the above as demos/talks with some of them have not been that useful. They all say they’re great and can do everything.

Thanks!