You should always take your own real estate agent with you when you go to visit new construction complexes. He/she needs to sign in with you and that way will get paid. Without an agent at the first visit, most developers will not pay a commission.
That being said, your agent can do some serious negotiating for you. He/she has a fudiciary responsibility to you first and foremost. The agents who work for the developer will work for you as they get a commission from all sales....but their fudiciary responsibility is to the developer.
All developers want to sell and should not turn down any offer. Ask for a lot of concessions - price, 1-2 years HOA dues paid by Seller, free upgrades, free storage (if one is available), etc. Arterra may give you some of these.....Negotiate with them!