-good loading system (not mandatory thanks to eyes, but helps.)
-remote (you will want to make as light as possible if you go with upgrades)
-Reliable woodsball electro
-Lack of fire modes
-Requires higher than average maintenance
i have had the MR3 for a little while now, and think that with time and care this could be one of the most useful scenario markers around.
FIRST IMPRESSIONS--The first thing you notice is the weight. This is by far one of the most heavy guns I've used. So, it may decrease your snapshooting speed slightly. The second thing i noticed is why it was heavy. The main body is metal and the front foregrip is made of the toughest plastic i have ever seen. You would probably need a hacksaw to cut the plastic, let alone the metal body. And did i mention this is probably the best looking mil-sim gun for its price out there?
ACCURACY--The stock barrel is larger-bore and a little loud, which translates into slight inaccuracy normally. Luckily, the marker is about average at air (or CO2) consumption. The stock is adjustable to 3 lengths and tilted slightly. However, it still prevents you from looking down the provided sight of the marker with a mask on, but that is nearly unsolvable. It's hooked on with one large silver screw, but that is more stable than it sounds. And, when buying barrels with this gun, make sure to bring it with you. The shroud on the front won't accept certain barrels if they have flare of some kind on them. (A.K.A. big flashy backs with a logo that sticks out or something)
GRIP--The trigger is 2 way adjustable so you can set it to your preference. The trigger guard is massive if you can't tell from the picture, i can fit 7 fingers into it. The back of the grip frame has the firing mode switch, (semi-eyes on, semi-eyes off, and full auto-eyes off) the charge port, and an LED light that shows your current firing mode. The grip frames are bendable plastic, and don't quite fit right to the grip. This leaves about.....maybe (guessing)1/2 centimeter of space between the cover and the frame? Because of the placement of the switch and charger, you can't just tape it or it would cover something important. So, if you are very worried about it, you might want to look for a new grip frame.
EYES--The electronic eyes work well, but are only usable one firing mode. Make sure to keep them clean, as paint will decrease its performance. On a side note, the eye cover is made of the same type of plastic as the grip, only thicker. So don't over tighten it, it will snap.
OTHER--Field striping is easy, requiring you to only remove the stock and and strip pin. The cocking system is unique; its a T-shaped metal thing you pull back on. I personally like this a lot as it adds to the mil-sim feel of the marker, and doesn't expose anything out from the body. The velocity adjuster is under the stock, standard allen-screw stuff. You are going to want to invest time into this gun. When it rips, it rips, and when it chops, it sucks. Standard cleaning should be enough. The front foregrip is HARD to get off. The rails are a nice addition. The Q-loader is hard to mount on it. The site actually recommends you saw off the front foregrip to expose the regulator, then attach it to that. I just bough the RAP4 adapter and it works great.
This gun combines the speed of electos with the durability, ergonomics, and looks of woodsball markers. The only real setback is the weight, which you get over with use. This is for experienced players how to properly take care of their equipment, and want to play in the woods. A great buy. My exact Final Score is 8.8