We are recompiling all of the ships back to LSL and will soon release a V14 update. The reason for this is because mono has severe issues in regards to initiation overhead and anything mono that is rezzed or enters a sim severely cripples it. More details can be found here...http://jira.secondlife.com/browse/SVC-3895
You have no idea how frustrating it is to have put all that work in these ships only to find out they don't run very well in a group battle. At least I know what the biggest problem is now so I can properly fix it. We also have been working on reducing the HUD to ship talk so the combination of these two methods will make battles much smoother.
We tested 3 LSL compiled ships using these methods in Obsidian Sea and found that border crossings to be much less painful, as well as the ships generally being more responsive as a whole. This will also do wonders for the machine gun equipped ships, as every single bullet they fire is mono, meaning massive overhead issues for the sim. This is often why in large melees the gatlings will get stuck firing in a loop and cripple the sim.
I would advise anyone who makes ICS compliant vehicles or weapons to try recompiling them back to LSL and see how much they improve. If you type crtl+shift+1 inworld you can measure the statistics and see it for yourselves. Note that this issue only concerns rezzing or sim border crossing. If you have something that is static and stays in one place, it should be just fine in mono.
Also note that if anything you wear has mono scripts in them, such as hair-resizers or AOs then they will cause considerable damage when you cross a sim border. Most hair-resizers have the option of killing all the scripts inside once you have it set the way you like it, however for AO issues I might recommend the Emerald viewer here...http://modularsystems.sl/index.php?option=com_content&view=article&id=3&Itemid=8
The reason why I recommend Emerald viewer is because it has a built in AO system, meaning you do not need to wear any scripts because it is all handled in the client. Not sure how much that actually helps but it is certainly worth a shot, if not for that then for the many other useful features that come with Emerald.
One last thing. It seems there are several alternatives for XStreet available.
http://www.osgrid.org/elgg/pg/generalstore/ -collection of freebie items
http://www.apez.biz -offers many more features such as banking, vendor systems, etc
http://www.texturesrus.net -offers over 80,000 individual textures
http://www.slapt.me/ -another nice alternative with over 18,000 items
Hmmm Apez.biz looks very promising, we will keep an eye on that one.