I've been looking at the various mag extensions available for the large-frame 10mm/45acp magazines to reduce the number of reload cycles a bit at an upcoming class. On one hand, I'm 99.9% certain the Arredondo +4 extensions would be reliable and work right out of the box. On the other hand, I'm having a very hard time spending $40 each on +4 extensions to expand $25 magazines.
The common alternatives seem to be the Pearce +2 at $9.50 and the Glockmeister +2 at $12, neither of which comes with a longer spring.
There's also the Kriss +17 extension, but I figure I'll hold off on that until Rogers next year.
Good/bad/indifferent experiences with any of the +2 extensions?
Given the new springs in my standard-capacity G21/41 magazines, should I be worried about spring pressure for the last few rounds with the +2 extensions?
These would be for range/class use, not for gaming in L10 or carry.