Its good, but it has a few problems.
Vanguards world is huge and doesn't make use of instancing. The game features many forms of mounts and transportation, horses you get at lvl 10, boats that players make, flying mounts you can rent and will soon be able to own, and a rift system that teleports you around the world.
The game also has an auctionhouse, bank, ingame email, and player housing, including large guild housing.
The graphics and the world in vanguard are also without peer. The world is build without zones or boundries. You can travel as far as you can see and in any direction with no artificial boxing as found in many games. In vanguard you can see for miles and pick a spot in the distance hop on your horse and travel to that location.
Adventuring combat is pretty standard far with attacks, starters, finishing moves. In addition there are reaction oriented moves like blocking or counterspelling that are done in response to events that occur during combat. Also there is a system or weakness creation and exploitation that enables a group of players to compliment each other creating weaknesses that other players can exploit to do additional damage.
The crafting system is rather deep and involved. You have a process oriented system where you do various actions to progress the quality or completeness of an item while dealing with complications that occur and making sure you don't run out of action points. The crafting system also has many recipes and various ways to customize recipes with various items found from adventuring of disassembling items.
The diplomacy system is a card game system where you interact with npcs to gain lore and various items that can be traded for cards, clothing or other equipment. Diplomacy system can effect general area's creating bufs for things like adventuring, crafting or diplomacy. Diplomacy can also be used in some dungeon areas to effect the difficulty of the dungeon or certain enemies.
The noticeable strengths:
Vanguards biggest strength is the broadness of the game. No other game has as much variety of activities players can choose from or the shear depth.
The world is huge, graphically pleasing, and immersive.
Vanguard also has a multitude of unique classes and races with numerous starting areas. You can start the game in different areas and have a unique game experience in each area.
BUT:
Vanguard was released too early. The developers ran out of money and had to ship the game before it was finished, fully debugged and polished.
At launch the system requirements were very high only the best computer systems could handle the game requirements. Even worse the graphics system performance and tuning were very poor. Graphical lag, hitching and pauses are commonplace. This is especially bad when going into a town or in an area with many people. And even on the lowest settings it can be a problem.
The high lvl game was thrown in quickly and the general story and quality of the quests is worse then the lower levels. There is a rushed feel to it and it has many bugs. Some quests are broken, some quests are very dull kill x of mob y. In an area you might find 20 quests all of this type.
The high lvl game has no raids.
Crafting and Diplomacy are also lacking polish or completeness. Crafting has numerous bugs and is not very polished.
Overall vanguards biggest problem is it was not complete.
Now several months later many of these problems have been addressed. Performance is significantly better and many bugs have been squashed. Raid content is being added in the next couple weeks and many quests are being revamped even some areas. overall the game has improved significantly.