I think today's manufactured RV are all pretty well made, and very similar. 5ers can be very expensive as well as reasonably priced based on size and interior decor and design.
Forest River is a reputable company. In your search, consider how much your tow vehicle is capable of handling, both the amount that can be loaded into the bed of the truck and the amount it can actually pull. And also consider how well the rig can stop also.
If you are considering a specific manufacturer go visit a dealer that sells them. Web site images are nice and full of information, but there's nothing like actually stepping inside and experience the moment. It helps if you can identify what floor plan you like, and after you find the floor plan, then start comparing against different manufacturers.
The last step is to compare floor plans and models against the cost you're willing to pay. Once you've been through these steps, you'll be able to plunge with confidence.
Others will chime in. Consider everything everyone will present to you. At the end, the decision will still be yours. Good luck in your quest, and enjoy this journey too. It's very exciting studying, planning, and searching for the right camper! It really is!