If your main goal is to go from point A to point B in the woods the Montana unit is more than you would ever use. I have used a wide range of units since they first hit the market and most all will get you where you need to go. I feel that 75% of the folks out there would do just fine with the most basic of units. The other 25% might want to consider the other end of the spectrum in GPS.
As for me, I simply had no idea what I was missing until I purchased a full featured unit with touch screen and mapping. Man, what a difference it has made in my outdoor world.
Where do these units shine from basic point A to point B models? The list is very long but remember, not all of these features benefit everyone. Each user would have to decide if they are worth the cost.
Point A to point B- I hunt and navigate in some very difficult terrain. Going from here to there is sometimes complicated by extreme hillsides/ swamps/ rivers and more. Mapping and topo features allow me to find a safe and easy way to get through these extreme locations or to get back to downed animals for recoveries. Going from A to B in a strait line where I hunt and guide is sometimes a very, very bad idea. A fantastic example of this feature occurred on the last blood trail in bear camp this year. A "strait line" return to the truck following the recovery of the bear (that had traveled well over a mile) would have meant traversing very steep hillsides with dangerous bluffs. A quick look at the GPS mapping showed a 4 wheeler trail off to one side that allowed for a easy downhill stroll to the truck. Mapping is HUGE when I track over long distances with a blood dog. Maps at a glance in the palm of my hand is something I use dozens (if not a couple of hundred) times per day.
Touch screen is something you have to experience to fully appreciate. I had no idea what I was missing until I got it. I would pay double on any unit to get it. It is 10X faster and 100X less frustrating. Here is an example... As I follow my dog on a blood trail I can mark waypoints at a fast walk without even looking at the unit. Coupled with mapping this feature is worth everything to me. I can now look down at a glance and tell where I have been, where I am going, the topo the animal has used and the frequency of blood sign. The Montana has a BIG screen and I like that. If you wanted a very similar unit with a smaller screen I would look hard at the Oregon model.
Wireless waypoint sharing is something the Montana and Oregon units feature. This is a very big deal when you are sharing 10-40 waypoints with other units when missing a single digit with typing the info can cause you VERY big problems. In years past, sharing 35 bear bait sites, two dozen tree stand locations or 20 off shore wrecks would have taken hours but now sharing waypoints wirelessly takes just seconds.
Nearby places of interest is a feature of the Montana that is certainly not necessary but very neat when you are somewhere you have never been. Historical places, fuel, camping and a long list of other items can be found with this feature.
I use the unit in blue water to find wrecks when fishing off shore. It is highly accurate and is a great feature that I depend on to get me home is some REALLY bad weather conditions. This is where a big screen shines.
Use of the camera is most likely something that many would simply not need but it has a place for some. Snapping a photo of a place (like bear bait 37) and then geo tagging it helps you and other that have not been there to see what is there like stand type, river crossing conditions, view of topography vs foliage etc. This could be helpful to some I am sure. Do not buy this feature on a unit for its value as a stand alone camera. it is not of high quality.
I use the unit for driving also. It requires a city navigation chip and a mount with speakers for voice navigation.
The units offer many more features that would take a month to write about here. Go on the internet and watch a few videos of these units in action for a real eye opener.
The Montana and other full featured units are not for everyone but for me and others that use them for their many features, they are a value at any cost.
Like others have stated, go and put your hands on the various units. I borrowed one 2 years ago and found out the value of the unit to me. Good luck finding a unit that fits your needs. Let me know if I can answer any questions you have regarding the Montana 650T unit
Here is the unit in action helping me to dance with a nasty weather cell.