The first 4 migrations worked well with the recommende migrator, but the 5th was really a pain. I costs me over a month until I decided to buy SP upgrade.
With this, after an hour everything was finished. It seems, that the hoster of the 5th domain is very strict, which results in plenty of time-outs. But the great advantage of SP upgrade is, that after a time-out you just hit the "back"-button of your browser and start the migration again. SP remembers where it has been and continues.
One hint: When you have restarted after a timeout, there is usually a DUPLICATE KEY error. Write down these Ids. About 25% of these records are not properly transferred. In my case 4 defect records of 30,000. Really not a big deal.
Some questions to the support even on a saturday have been answered within an hour.
I wish I have bought it before the first migration. SP would have saved me plenty of time.
Thumbs up for this excellent extension.
You have full control over the topics of the incoming links (e.g. no casino, no adult, no miltary, no politic, whatever you like)
You can even reject single incoming and outgoing links, which you do not like.
I have tested the module 2.2.3 with joomla 1.5 and PHP/HTML-sites.