This seems like a no brainer, as it adds no value to the Marketing team to see the GUID of all the synced Lookup fields from the Dynamics CRM integration with CRM.
So, to see an actual value, well, it makes 100% difference in the product.
We had to go with a custom integration and work with a middleware, Vertify, which can pass data properly and provider triggers off marketo custom objects. Marketo native integration was sold to us as it could do everything. Surprise, it did very little. If you can, I recommend discussing with your team about implementing a middleware (thumbs up to Vertify for being amazing) to help you get the data you need into Marketo as you want to see it.
thanks @Ecary - yes its frustrating that Adobe/Marketo pitch the native integrators as perfectly workable and yet they have so many issues (the powerbi one was even withdrawn from availability!) - Vertify have been great when i've talked to them before - hadnt thought on integration tho - its certainly something i'll consider with fivetran/matillion etc. from a data integration perspective!