IMHO, the Gen 1 HDS 8’s are wonderful units. I run 1 along with 2 HDS 10’s and haven’t experienced a single problem.
Since the new Gen 2’s came out, it really knocked down the value of our Gen 1’s (2011 and older) so maybe check around on someplace like ebay to see what they are going for.
The HDS 8 has broadband HD sonar and as mentioned in ealrier post, you would need to add the Lowrance LSS 1 structure scan unit to get SI & DI Structure scan.
My $.02, it the price is somewhat close to the new HDS 8 Gen 2, go new (much faster and other advanced benifits). I beleive Lowrance is still offering pretty good rebates. If you feel it’s a really good deal, go with the 2011, guessing you wouldn’t be dissapointed.
Good luck