Portfolio's comms are notoriously hit and miss so I wouldn't say you could expect a better service than dealing directly with the SP. You also get the downside of not speaking direct to the provider about services. I have in the past found Portfolio to be a bit coy about confirming services. Many of their girls have AW profiles, which in an ideal world would give you that detail, but Natalia's lists CIM for example and she resolutely doesn't offer that. You can also expect to be asked for a deposit as an agency first timer.
Alice would be my recommendation, from their current line up but she is away until 17th Aug according to her profile. Not sure I have ever seen a review of Nia.
