diff --git a/pyzipline/rest_adapter.py b/pyzipline/rest_adapter.py
index 283a402..bb09265 100644
--- a/pyzipline/rest_adapter.py
+++ b/pyzipline/rest_adapter.py
@@ -53,11 +53,7 @@ class RestAdapter:
         full_url = self._url + endpoint
         headers = {'Authorization': self._token}
 
-        log_line_pre = f"method={http_method}, url={full_url}, params={params}"
-        log_line_post = ', '.join((log_line_pre, "success={}, status_code={}, message={}"))
-
-        try: # Log HTTP params and perform an HTTP request, catching and re-raising any exceptions
-            self._logger.debug(msg=log_line_pre)
+        try: # Perform an HTTP request, catching and re-raising any exceptions
             # will eventually refactor this to use asyncio/aiohttp instead for async operation
             response = requests.request(method=http_method, url=full_url, verify=self._enforced_signing, params=params, headers=headers, json=data)
         except requests.exceptions.RequestException as e:
@@ -67,14 +63,15 @@ class RestAdapter:
         try: # Deserialize JSON output to Python object, or return failed Result on exception
             data_out = response.json()
         except (ValueError, JSONDecodeError) as e:
-            self._logger.error(msg=log_line_post.format(False, None, e))
             raise PyZiplineError("Could not decode response from Zipline server") from e
 
         # If status_code in 200-299 range, return success Result with data, otherwise return failed Result with message
         is_success = 299 >= response.status_code >= 200
 
-        self._logger.debug(msg=log_line_post.format(is_success, response.status_code, response.reason))
-        return Result(success=is_success, status_code=response.status_code, message=response.reason, data=data_out)
+        if is_success:
+            return Result(success=is_success, status_code=response.status_code, message=response.reason, data=data_out)
+        else:
+            return Result(success=is_success, status_code=response.status_code, message=data_out['error'], data=data_out)
 
     def get(self, endpoint: str, params: Dict = None) -> Result:
         """Make a GET request to the Zipline server. You should almost never have to use this directly.
diff --git a/pyzipline/zipline.py b/pyzipline/zipline.py
index cebe5d9..9b2c5ef 100644
--- a/pyzipline/zipline.py
+++ b/pyzipline/zipline.py
@@ -1,6 +1,7 @@
 import logging
+import json
 from pyzipline.rest_adapter import RestAdapter
-from pyzipline.errors import PyZiplineError, FeatureDisabledError
+from pyzipline.exceptions import PyZiplineError, FeatureDisabledError
 from pyzipline.models import *
 
 class ZiplineApi:
@@ -28,11 +29,15 @@ class ZiplineApi:
     def get_user(self, user_id: int) -> User:
         """Get a user by ID
 
+        /// admonition | Requires Administrator
+            type: danger
+        ///
+
         Args:
             user_id (int): Integer ID of the user to retrieve
 
         Returns:
-            :class:`pyzipline.models.User`: The user with the given ID
+            User: The user with the given ID
         """
         result = self._rest_adapter.get(endpoint=f"user/{user_id}")
         return User(**result.data)
@@ -40,11 +45,18 @@ class ZiplineApi:
     def get_self(self) -> User:
         """Get the currently authenticated user
 
+        /// admonition | Requires Authentication
+            type: warning
+        ///
+
         Returns:
-            :class:`pyzipline.models.User`: The currently authenticated user
+            User: The currently authenticated user
         """
         result = self._rest_adapter.get(endpoint=f"user")
-        return User(**result.data)
+        if result.status_code == 200:
+            return User(**result.data)
+        elif result.status_code == 401:
+            raise ValueError(result.message)
 
     def check_user_exists(self, username: str, invite: str = None) -> bool:
         """Check if a user exists by username
@@ -55,20 +67,25 @@ class ZiplineApi:
 
         Raises:
             FeatureDisabledError: Raised when registration or invites are disabled on the Zipline instance
-            PyZiplineError: Raised
+            PyZiplineError: Raised if the API changes, causing a breaking change in this method
+            ValueError: Raised when the username is not present, or the invite code is invalid/not present and invites are enabled
 
         Returns:
             bool: True if user exists, False if not
         """
-        params = {'username': username} if invite is None else {'username': username, 'code': invite}
-        result: Result = self._rest_adapter.get(endpoint=f"user/check", params=params)
+        data = {'username': username} if invite is None else {'username': username, 'code': invite}
+        result: Result = self._rest_adapter.post(endpoint=f"user/check", data=data)
         if result.status_code == 200:
-            return bool(result.data['success'])
-        elif result.message == 'user resistration is disabled' or result.message == 'invites are disabled':
-            raise FeatureDisabledError(result.message)
+            return False
         elif result.message == 'username already exists':
             return True
+        elif result.message == 'user registration is disabled':
+            raise FeatureDisabledError('user registration or invites are disabled')
         elif result.message == 'invalid invite code':
-            raise ValueError(result.message)
+            raise ValueError(result.message + "(most likely doesn't exist)")
+        elif result.message == 'no code':
+            raise ValueError('invite code not provided')
+        elif result.message == 'no username':
+            raise ValueError('username not provided')
         else:
             raise PyZiplineError(result.message)