diff --git a/README.md b/README.md
index d6a11d2..2b1edc5 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,6 @@
 Go-EBML
 =======
-
-A marshaler and unmarshaler for [EBML](http://ebml.sourceforge.net/).
+A marshaler/unmarshaler for [EBML](http://ebml.sourceforge.net/).
 
 It's quite simple to use:
 ```go
@@ -18,16 +17,9 @@ func ExampleMarshal() {
 	DoDad.ThingaMabob = "huzah"
 	DoDad.HumDinger = -92387
 
-	b, err := ebml.Marshal(*DoDad)
-	if err != nil {
-		fmt.Println(err)
-	}
+	b, _ := ebml.Marshal(*DoDad)
 	fmt.Printf("0x%x\n", b)
 
-	err = ebml.Unmarshal(b, DoDad)
-	if err != nil {
-		fmt.Println(err)
-	}
 	// Output:
 	// 0x3f00009442428301117042438568757a6168424483fe971d
 }
@@ -47,10 +39,7 @@ func ExampleUnmarshal() {
 		HumDinger   int     `ebml:"4244"`
 	})
 
-	err := ebml.Unmarshal(data, DoDad)
-	if err != nil {
-		fmt.Println(err)
-	}
+	ebml.Unmarshal(data, DoDad)
 	fmt.Printf("%v\n", DoDad)
 	// Output:
 	// &{0 70000 huzah -92387}
@@ -59,9 +48,19 @@ func ExampleUnmarshal() {
 ```
 
 
+Caveats
+-------
+If an EBML DTD specifies a value as an unsigned integer, you must use a uint 
+type. For example: the uint32 8388608 and int -8388608 may encode to identical
+0x800000 24 bit arrays in an EBML stream.
+
+EBML does not have a boolean type, but booleans are commonly defined in DTDs 
+as zero or non-zero usigned integers.
+
+
 Limitations
 -----------
-Default values are not supported yet, as per the EBML RFC:
+Default values are not implemented yet, as they are defined in the EBML RFC:
 > Every non-container MAY be assigned a default value. If so, its
 > value will be added to the interpretation of the EBML data if no
 > element with another value exists in the data.
diff --git a/decode.go b/decode.go
index fe63b51..1b8cf2b 100644
--- a/decode.go
+++ b/decode.go
@@ -32,7 +32,8 @@ func readIdFrom(r io.ReadSeeker) (int, Id) {
 		if err != nil {
 			encError(err.Error())
 		}
-		decError(fmt.Sprintf("invalid Id at reader position %x or EBMLMaxIDLength > 4, read byte %x", p, buf[0]))
+		r.Read(buf)
+		decError(fmt.Sprintf("invalid Id at reader position 0x%x or EBMLMaxIDLength > 4, next 8 bytes 0x%0.2x", p, buf))
 	}
 	var nn int
 	nn, err = r.Read(buf)
diff --git a/ebml.go b/ebml.go
index 4ae7bf5..53cd1cb 100644
--- a/ebml.go
+++ b/ebml.go
@@ -55,7 +55,7 @@ func (id Id) Bytes() []byte {
 	case id < 0x0800000001:
 		l = 4
 	default:
-		panic("invalid element ID")
+		panic(fmt.Sprintf("invalid element ID %s", id))
 	}
 	b := make([]byte, l)
 	for l > 1 {
diff --git a/ebml_test.go b/ebml_test.go
index f0f44eb..aa34d0f 100644
--- a/ebml_test.go
+++ b/ebml_test.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"github.com/3M3RY/go-ebml"
 	"io"
+	"io/ioutil"
 	"math/rand"
 	"reflect"
 	"testing"
@@ -54,10 +55,6 @@ func ExampleMarshal() {
 	}
 	fmt.Printf("0x%x\n", b)
 
-	err = ebml.Unmarshal(b, DoDad)
-	if err != nil {
-		fmt.Println(err)
-	}
 	// Output:
 	// 0x3f00009442428301117042438568757a6168424483fe971d
 }
@@ -136,7 +133,6 @@ func TestUint(t *testing.T) {
 		}
 
 		err = ebml.Unmarshal(buf, &out)
-		//err = Unmarshal(buf, &out)
 		if err != nil && err != io.EOF {
 			t.Fatalf("marshal int %d: %s\n buf: %x", I, err, buf)
 		}
@@ -146,3 +142,59 @@ func TestUint(t *testing.T) {
 		}
 	}
 }
+
+type benchTestStruct struct {
+	EbmlId ebml.Id `ebml:"81"`
+	A      uint    `ebml:"4011"`
+	B      int64   `ebml:"200011"`
+	C      int64   `ebml:"10000011"`
+	D      string  `ebml:"800000000"`
+}
+
+func BenchmarkEncoding(b *testing.B) {
+	var test benchTestStruct
+	rand.Seed(time.Now().UnixNano())
+
+	test.A = uint(rand.Int63())
+	test.B = rand.Int63()
+	test.C = 1 - rand.Int63()
+	test.D = "of ships and sails and whether pigs have wings"
+
+	var err error
+	b.ResetTimer()
+	enc := ebml.NewEncoder(ioutil.Discard)
+	for i := 0; i < b.N; i++ {
+		err = enc.Encode(test)
+		if err != nil {
+			b.Fatal(err.Error())
+		}
+	}
+}
+
+func BenchmarkDecoding(b *testing.B) {
+	var control benchTestStruct
+	rand.Seed(time.Now().UnixNano())
+
+	control.A = uint(rand.Int63())
+	control.B = rand.Int63()
+	control.C = 1 - rand.Int63()
+	control.D = "of ships and sails and whether pigs have wings"
+
+	buf, err := ebml.Marshal(control)
+	r := bytes.NewReader(buf)
+	b.ResetTimer()
+
+	dec := ebml.NewDecoder(r)
+	for i := 0; i < b.N; i++ {
+		var test benchTestStruct
+		err = dec.Decode(&test)
+		if err != nil {
+			b.Fatal(err.Error())
+		}
+
+		if !reflect.DeepEqual(control, test) {
+			b.Fatal("not equal")
+		}
+		r.Seek(0, 0)
+	}
+}