I drove by the Brea loft building site, but didn't go in for a visit. I think the sales office won't be open until later this month or next month. I get my car fixed at Jax Auto across the street from there, but don't use the car wash nearby. I use the car wash by Lambert & 57 FWY because it's closer to my work.
I've seen several recent developments with commercial space under residental, in Fullerton by Malvern & Basternchury, and Downtown Fullerton near the rail station. IMO the tract by Downtown Fullerton isn't that great because it's kinda concealed from Harbor blvd and next to the rail tracks. If it faced Harbor Blvd, I think the offices would be far more attractive and you could run a little specialized boutique shop as a hobby.
Personally, I prefer Downtown Fullerton over Downtown Brea. Fullerton gives me a better "vibe", plus I graduated from Fullerton College & CSUF. It's near rail station, 91 FWY, 57 FWY, major retail outlets (Costco) by Harbor & Orangethrope, decent selection of restaurants, and a little bit of night life. On the downside, there's no supermarkets by Downtown Fullerton, and most of the housing near it are oldish, except the rental apartments.
Downtown Brea, on the other hand, only has access to 57 FWY nearby. But the development is newer and you have many choices of recently built housing avail. There's also a major shopping center and mall nearby. Compared to Harbor Lofts, I think I'd gladly opt for Fullerton or Brea over Anaheim. >_<