Is TuxGuitar any good?
During the same time, TuxGuitar had 3.4/5 stars in the Softpedia user ratings. As of August 2016 the program has 4.7/5 stars on SourceForge. Reviewers at Software Informer gave version 1.0 of TuxGuitar 5/5 stars, praising the "very easy to use interface" and "very advanced functions" of the program.
How do I change the tempo on TuxGuitar?
Press F9 and then select simple mode (which is what you probably want more of) or training mode, select the tempo you would like and whether or not it increases each loop and then just below that it asks for which bars you want to loop so select whichever ones you want and done.