diff --git a/MODERNIZATION.md b/MODERNIZATION.md
index 2a0ddb1..1b398dd 100644
--- a/MODERNIZATION.md
+++ b/MODERNIZATION.md
@@ -78,7 +78,7 @@ Also fix the test files:
 
 ---
 
-## 5. Use `strings.ReplaceAll` instead of `strings.Replace(..., -1)` (Go 1.12+)
+## ~~5. Use `strings.ReplaceAll` instead of `strings.Replace(..., -1)` (Go 1.12+)~~ (DONE)
 
 `strings.ReplaceAll` is a clearer, more idiomatic function for replacing all occurrences.
 
@@ -104,7 +104,7 @@ Also applies to `bench_test.go` lines 229-230.
 
 ---
 
-## 6. Use `strings.Builder` instead of `bytes.Buffer` for String Building
+## ~~6. Use `strings.Builder` instead of `bytes.Buffer` for String Building~~ (DONE)
 
 `strings.Builder` (Go 1.10+) is purpose-built for building strings and avoids the `[]byte` to `string` copy that `bytes.Buffer.String()` performs.
 
@@ -396,8 +396,8 @@ If `Build` returns an error, `productDao` will have nil function fields. Subsequ
 - #11 — Update dependencies
 
 **Lower priority (cleanup):**
-- #5 — `strings.ReplaceAll`
-- #6 — `strings.Builder`
+- ~~#5 — `strings.ReplaceAll`~~ *(DONE)*
+- ~~#6 — `strings.Builder`~~ *(DONE)*
 - #9 — Delete `cmp/errors.go`
 - #10 — Deprecation annotations
 - #12 — Testing improvements
diff --git a/bench_test.go b/bench_test.go
index 008e21f..3a35660 100644
--- a/bench_test.go
+++ b/bench_test.go
@@ -226,8 +226,8 @@ func (spd standardPersonDao) GetByAge(db *sql.DB, id int, ages []int, name strin
 
 	inClause := strings.Join(params, ",")
 
-	finalQuery := strings.Replace(startQuery, ":ages:", inClause, -1)
-	finalQuery = strings.Replace(finalQuery, ":id:", fmt.Sprintf("$%d", len(ages)+2), -1)
+	finalQuery := strings.ReplaceAll(startQuery, ":ages:", inClause)
+	finalQuery = strings.ReplaceAll(finalQuery, ":id:", fmt.Sprintf("$%d", len(ages)+2))
 
 	args := make([]any, 0, len(ages)+2)
 	args = append(args, name)
diff --git a/builder.go b/builder.go
index 092dc0d..dbdd44f 100644
--- a/builder.go
+++ b/builder.go
@@ -1,7 +1,6 @@
 package proteus
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"go/scanner"
@@ -64,7 +63,7 @@ type posType interface {
 }
 
 func buildFixedQueryAndParamOrder(ctx context.Context, query string, nameOrderMap map[string]int, funcType posType, pa ParamAdapter) (queryHolder, []paramInfo, error) {
-	var out bytes.Buffer
+	var out strings.Builder
 
 	var paramOrder []paramInfo
 
@@ -73,7 +72,7 @@ func buildFixedQueryAndParamOrder(ctx context.Context, query string, nameOrderMa
 	// ending on a single \ means the \ is ignored
 	inEscape := false
 	inVar := false
-	curVar := []rune{}
+	var curVar strings.Builder
 	hasSlice := false
 	for k, v := range query {
 		if inEscape {
@@ -86,11 +85,11 @@ func buildFixedQueryAndParamOrder(ctx context.Context, query string, nameOrderMa
 			inEscape = true
 		case ':':
 			if inVar {
-				if len(curVar) == 0 {
+				if curVar.Len() == 0 {
 					//error! must have a something
 					return nil, nil, stackerr.Errorf("empty variable declaration at position %d", k)
 				}
-				curVarS := string(curVar)
+				curVarS := curVar.String()
 				id, err := validIdentifier(ctx, curVarS)
 				if err != nil {
 					//error, identifier must be valid go identifier with . for path
@@ -137,13 +136,13 @@ func buildFixedQueryAndParamOrder(ctx context.Context, query string, nameOrderMa
 				}
 
 				inVar = false
-				curVar = []rune{}
+				curVar.Reset()
 			} else {
 				inVar = true
 			}
 		default:
 			if inVar {
-				curVar = append(curVar, v)
+				curVar.WriteRune(v)
 			} else {
 				out.WriteRune(v)
 			}
@@ -187,7 +186,7 @@ func doFinalize(ctx context.Context, queryString string, paramOrder []paramInfo,
 			sliceMap[fixNameForTemplate(v.name)] = 1
 		}
 	}
-	var b bytes.Buffer
+	var b strings.Builder
 	err = temp.Execute(&b, sliceMap)
 	if err != nil {
 		return "", err
@@ -207,7 +206,7 @@ const (
 
 func joinFactory(startPos int, paramAdapter ParamAdapter) func(int) string {
 	return func(total int) string {
-		var b bytes.Buffer
+		var b strings.Builder
 		for i := 0; i < total; i++ {
 			if i > 0 {
 				b.WriteString(", ")
@@ -221,10 +220,10 @@ func joinFactory(startPos int, paramAdapter ParamAdapter) func(int) string {
 
 func fixNameForTemplate(name string) string {
 	//need to make sure that foo.bar and fooDOTbar don't collide, however unlikely
-	name = strings.Replace(name, "DOT", "DOTDOT", -1)
-	name = strings.Replace(name, ".", "DOT", -1)
-	name = strings.Replace(name, "DOLLAR", "DOLLARDOLLAR", -1)
-	name = strings.Replace(name, "$", "DOLLAR", -1)
+	name = strings.ReplaceAll(name, "DOT", "DOTDOT")
+	name = strings.ReplaceAll(name, ".", "DOT")
+	name = strings.ReplaceAll(name, "DOLLAR", "DOLLARDOLLAR")
+	name = strings.ReplaceAll(name, "$", "DOLLAR")
 	return name
 }
 
diff --git a/line_logger.go b/line_logger.go
index 1c1ef14..e1dc715 100644
--- a/line_logger.go
+++ b/line_logger.go
@@ -1,7 +1,6 @@
 package proteus
 
 import (
-	"bytes"
 	"log/slog"
 	"strings"
 	"testing"
@@ -12,7 +11,7 @@ func RegisterLineLogger(t *testing.T) func() []string {
 	t.Cleanup(func() {
 		slog.SetDefault(defaultLogger)
 	})
-	var buf bytes.Buffer
+	var buf strings.Builder
 	logger := slog.New(slog.NewTextHandler(&buf, &slog.HandlerOptions{
 		Level: slog.LevelDebug,
 	}))
diff --git a/template_test.go b/template_test.go
index e8e56d1..fc26cce 100644
--- a/template_test.go
+++ b/template_test.go
@@ -1,9 +1,9 @@
 package proteus
 
 import (
-	"bytes"
 	"fmt"
 	"html/template"
+	"strings"
 	"testing"
 )
 
@@ -19,7 +19,7 @@ func TestTemplate(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	var b bytes.Buffer
+	var b strings.Builder
 
 	err = tmpl.Execute(&b, map[string]any{"vals": 3})
 	if err != nil {