I am interested in buying one of these portable speaker sets. Can anyone give me any info (link to a review, or personal opinion) on either of these? Which is the newer model? As far as I can tell, the only difference between them (besides the $10 price difference) is that the 77 has 4w of power vs. 2w for the 70, and the 77 comes with an ac adaptor. Are there any other differences? Are either of these worth the cost (msrp for the 70 is $79, $89 for the 77). Any other recommendations for portable battery powered speakers to use with my minidisc player? Thanks in advance for any help.