Which one is right for Brycen???

I thought some decisions in the past were hard, but I think this is by far the most difficult decision we have ever had to make. While some people (including myself until recently) think all of this would probably be easy because all we want is for our son to be able to communicate with us, I am finding out it is so much more difficult than any other decision we have ever had to make for him!! Choosing to get him evaluated by an Autism team was easy, choosing to start speech and OT was easy, starting PECS was easy...ok, so none of this is really "easy" because it all comes with a lot of emotions, grieving, acceptance, educating, adjusting, etc. But all of these were just a given when it came to Brycen's diagnosis and since we live in small towns, we don't have options of various therapies so you take what you have available...and lucky for us that we have loved both of the places he has received his speech and OT.
Now we are making a decision that could either "make or break" his communication skills. The decision to start medications has been hard, but with medications, we can do more trial and error over time. With this device, the decision we make now has to be the right one for at least 5 years. It's almost like investing in a car or house...will it fit our needs, does it have enough room to grow with us, will it be durable and reliable...so many things to consider also with a device. We have to take into account things about Brycen that we aren't even sure about because he can't tell us! We commit ourselves to something that we think meets his needs and he can use, but what if we find out in a year that the other device's options seem to meet his needs better at that time?! We can't just trade it in and get a new one like you can a car or even a house!
We already made the decision several weeks go that we needed to go with a higher-tech device because of the "5 year rule" and we knew we wanted to meet with two different companies to view at least 2 different machines to make comparisons. Those were the easy decisions:)
I am getting so emotional and so stressed out over this decision...I keep crying when I think about the possibility of it not meeting his needs or of him getting frustrated with it to the point of causing him to regress. I don't even know who I can share these feelings with because I don't know how many people really and truly understand how much this is affecting me. Even the two reps we have talked to don't have "personal" experience with choosing one. Our speech therapist has been wonderful to be at both of these appointments, to do her research, to ask amazing questions that I would never have thought of by using her experience with other people/kids and devices. I'm crying just typing out this post because of how worried I am. Choosing something like this should make me feel excited and make me feel like I am opening up doors for Brycen that he doesn't have right now...so why do I feel like a failure as his mom when I am upset about it??
I do want to explain that both of these machines have wonderful capabilities to grow with Brycen! They each have pros and cons, they each are very visual for him, they each can be adapted somewhat to meet his needs and have some special features that we know would benefit him. The problem is that each person that needs a device is so unique and these companies do what they can to mesh that into one machine that could work for the majority of people. If I could take a few features of the first one and add that to a few features of the second one, then this decision wouldn't be so hard because I KNOW those are the features that would benefit Brycen now. But that's another problem I am having...what may benefit him now may not be the things that will work for him in a year or two! I have to take into account so many aspects of his life, the different situations he will use the device in, how easy is it for others like his teachers and my mom to use with him, will I get frustrated programming it (because if he sees me frustrated, then of course he will become frustrated), the fact he "sees" things in vertical not horizontal...so much to consider and of course there are those unanswered questions we have about what his next 5 years will be like and how much he will progress, so how much can grow with him! When I talked to Mike after the appt today, he immediately asked how did Brycen react to the machine today and that should help make the decision. I wish it was that easy...but unfortunately, Brycen was having an "off" day today. We noticed before even showing him the device that he was mellow, not verbalizing any sounds, didn't even run down the hallway like he always does when we head to the therapy room. The other time, he was happy, verbalizing a lot of sounds, using his few signs more, etc. On that day, he took over the machine and used it like he knew exactly what to do. Today, all he wanted to do was rub the smooth surface, push a few buttons, and then ignore it. I can't even let that help me make the decision since it was obvious his mood and abilities were completely different each day.
Just reading over this is making me cry again so I think it's time to finish this up. Below you will find links to both devices...unfortunately the links don't give you a real picture of how it can be used and what we will have programmed for Brycen, but at least you can see what I am contemplating. Thanks for "reading" me out! Again, I know this seems like it shouldn't take over so much of my emotions and thoughts right now, but this is a very, very difficult decision that pretty much affects Brycen's life for years and his ability to communicate. I just wish some there was some magical "sign" to tell me what is right for Brycen!

http://www.talktometechnologies.com/UserFiles/docs/Alt-Chat_brochure.pdf
http://www.dynavoxtech.com/products/maestro/features.aspx