The short answer is -
Let me explain.
For beginners, using the Bathmate Hydropump is definitely a comparable substitute for manual jelqing.
In fact, using the Bathmate for 12-15 minutes is certainly a more efficient way to gain size (especially girth).
This is because beginners are subject to "newbie gains" and will gain very quickly regardless of what their PE routine is.
The first .5" comes VERY QUICKY (about 2-3 months of ~daily Bathmate use).
The next .5" take a little longer (about 4-6 more months of ~daily Bathmate use).
Veterans to male enhancement (guys who have already gained over an inch in size), however, are not so lucky.
As I mentioned, achieving the second inch is much more time consuming and demanding.
Bathmate will definitely expedite the process, but you will almost certainly need to develop some sort of jelqing routine.
In fact, jelqing just prior to using the Bathmate, is an effective and advanced way to get even greater expansion. This should only be considered by guys that have used the Bathmate for a while however.
For example, you can get more sustained gains by jelqing about 5 minutes before using the Bathmate. If you want to avoid water retention, it is advisable to split your Bathmate session up into 2-3 shorter sessions. This can be nicely combined with jelqing. For instance, you could split up a 15-minute session into 3x5 minutes and do 5-minute jelqing sessions before, in between and after for much more sustained gains.
Simply using the Bathmate is adequate and suitable replacement for manual jelqing exercises until you gain your first inch.
The ultimate and fastest gains can be had by combining both jelqing and Bathmate into a regular routine.
For more information on all the models of the Bathmate Hydropump, check out Good Looking Loser's Review and FAQ.
Leave any questions you have in the blog comments section. I'll be happy to answer them.