I'me migrating my UBB.Classic 6.7.3 board to UBB.Threads 7.5.7
I have over 15000 registered users and over 500.000 posts, with about 80 Gb traffic each month.

I've done a testrun with the importers script which ends soon with the following error:

UBB Message We encountered a problem. The reason reported was
Script:
Line#:
SQL Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'TYPE=heap' at line 17
SQL Error #: 1064
Query: create table ubbt_ONLINE( ONLINE_DISPLAY_NAME varchar(64) not null, USER_ID int(9) not null, ONLINE_LAST_ACTIVITY int(9) default '0' not null, ONLINE_SCRIPT_NAME varchar(64), ONLINE_USER_TYPE varchar(1) not null, ONLINE_BROWSING_FORUM varchar(100), ONLINE_USER_IP varchar(15), onlINE_AGENT varchar(255), ONLINE_REFERER varchar(255), ONLINE_POST_ID int(9), ONLINE_POST_SUBJECT varchar(255), UNIQUE Oindx1 (ONLINE_DISPLAY_NAME), INDEX Oindx2 (ONLINE_LAST_ACTIVITY), INDEX Oindex3 (USER_ID), INDEX type_index(ONLINE_USER_TYPE) ) TYPE=heap

After some google research i've edit these files:
altertable-7.1.php
createtable.php

and changed the TYPE=heap to ENGINE=heap.
Things went well after that. But after reading some documentation about mysql i can also change TYPE=heap
into ENGINE=memory

Question:
what's the best solution? ENGINE=heap OR ENGINE=memory?
Thanks for your help!

PS When can we expect Threads 7.6.x ?