Jond105, I like the range of eyepieces that you have. The 11mm fills in a gap.
I also like having a similar range of eyepieces.
For higher magnifications, flexibility is needed depending on sky conditions. Even though some eyepiece f.l. may look too close together, they actually are not.
Your 4.7mm gives 382x and your 6.7mm gives 268x. You have a gap there too.
Maybe get a 5.5mm for that gap. At 327x it is almost an exact split between the other two.
I, myself, don't care for, and don't use barlows.
Let's say an older 5mm eyepiece doesn't have a lot of eye relief. Using a 2x barlow with a 10mm will give you the same magnification with a better eye relief.
But todays eyepieces, even at 5mm have very good eye relief.
These are the ES eyepieces that I have: 3mm, 4.5mm, 5.5mm, 6.5mm 8.8mm 14mm and a 24mm. They cover the range in magnification that I want. With my 130 with a 910 f.l., I actually want to get a 3.6mm eyepiece. It will fill in the gap between 300x and 200x. Having a eyepiece with 250x would be great.