Microsoft AX and Business Connector / Enterprise Portal / Application Integration Platform

I have been working for a while on a project aimed at integrating AX with the Internet.

The company that delivered the AX decided to use the Business Connector (BC.net) directly on my side of the backend.

I searched a bit and for me it looks like we should be using Application Integration Framework (AIF) / Enterprise portal (EP) - this is because I understand that BC is not built for multi-user users like on the web, but has to be implemented with a session wrapper like EP - and also it has to run on LAN and cannot connect over WAN.

Any comments on this?

- -EDIT- Additional information:

Oh sorry - new to stackoverflow - didn't see you comment on my question.

I am doing this from scratch. The original plan was to create a model and send objects directly from AX through BC to my data layer, but since BC cannot pass anything else then Axaptaobjects, we decided to serialize XML, send as string with BC and then deserialize with my data layer.

Everything works now, but stability and performance really suck - and I'm afraid that the company supplying the backend (BC -> AX) is doing something really wrong ...