I have started using this for over 6 months and in the beginning when the integration was under the "old version" , the stability and performance of the app is usually up to the standard with occasional minor glitches where manual work has to be done in Xero.
However, once OneSaaS has moved to a new integration platform in February 2019, the quality of the integration has greatly diminished where it is creating a lot of extra workload and the level of confidence for the app has greatly dropped for me because there have been missing invoices that are not synced into Xero for unknown reasons until you contact support!
In addition, the lead time for support to reply / resolve issues are much longer compared to 3-4 months ago.
Product sync on the new integration is extremely poor, as the mapping of the products are not as customized as before.
The product description on shopify is now being synced into Xero's product description, suspecting this is due to the majority of the users for this integration are pushing for this change so it is now done this way, where it is not suitable for minority users of the integration.
Depending on your actual needs, this app could be useful or devastating to your workflow.
Would still recommend this app as long as it's suitable to your company's workflow
OK, so OneSaas WILL let you connect multiple Shopify stores to your accounts package (in our case Xero) BUT it won't transfer refunds of Shopify fees - you have to do this manually.
Also bear in mind that if you have 2 or more Shopify stores you would ideally want the sales for each store to be allocated to a different sales code within your accounts package so that you can see which sales came from which store. Sadly OneSaas will only allow you to allocate all sales to single sales code so you have to go into your accounts package manually and move things around. OneSaas will however let you add a prefix to each order number to make this a little easier.
So the claim on their website that OneSaas will completely automate your online sales isn't entirely true!
That said their online support is excellent and questions are answered very quickly.