What are you using for a router and what type of bits, 1/4" shank? You have to be careful reducing the thickness of the router table, particularly if its made out of something like MDF or particle board/melamine or plywood. It won't have the necessary strength. The table top also has to be straight and flush or the work won't make full contact. If it sags at the bit, the table won't be of much use. The hole in the table has to be large enough for larger bits and the collet. This could be an easy cure for you. With any bit, it shouldn't be allowed to bottom out in the collet, they should be pulled up a small amount to prevent the collet from jamming and a stuck bit. You should grip at least 2/3 of the shank length.
The collet extensions work well except for large heavy bits, like panel raisers. Slight imbalance can be exaggerated. Without a plate or lift, you still have to reach under to loosen the router base and you don't want to forget to tighten it after setting the bit height or the router will be on the floor as soon as you hit the switch. If this ever happens, you could bend the extension, not to mention a running router bouncing around. Having the cord unplugged can remind you to tighten the base. Be careful to check the switch on any tool where the switch may be left on before plugging in. Always make sure you unplug any power tool when changing knives, blades or bits, never trust a switch of any kind.
I started making and using router tables long before there were any commercial ones, router lifts or plates. I still use one without any of those. Mostly because I do things on my router table most folks wouldn't need to do. A router plate would interfere with setting up starter pins, screwing down material supports and other weird stuff I might do. When you have a solid table top with a large hole, there are times, particularly with small pieces, that you need a tighter hole around the bit. When I have that situation, I'll add a temporary top like a piece of Formica with a small bit hole.
There are some quick change router collets that replace your standard collet and bits are secured with a hex key. They aren't cheap but make a big difference in above the table bit changes, no wrenches. I prefer these to the collet extensions which are like adding a large extra bit to the router. You don't have to worry about bent shafts, run out or imbalance. These replacement collets are specific to router brands.
Last edited by Hammer1; 01-19-2013 at 10:06 AM.