I bought my 551 Grip nearly seven years ago as my first BM. It would be in my drawer alone for nearly five years, until a BM 201 Activator+ joined it. Both, brand new, were dull as can be. It was a year back when I finally got around to sharpening them on my recently acquired Sharpmaker. The Grip's 440C and the Act+'s D2 took a while. Both are great users - finally. I recently added two more BMs - a 630 Skirmish and 635 mini-Skirmish - definite keepers, their S30V blades delivered new from the box as hair razors.
I really liked the BM Grip's AXIS lock - nearly as well as a lockback. Now, after some use, I may really like it. The large handle, required to let in the SS liners that support the AXIS lock, may just be too much for some. It is comfortable - to me. I remove clips, so I cannot speak to the clipped in pocket carry convenience of any of them. The Skirmish/mini-Skirmish are great - I highly reccomend them, but they run $165-$250 now on the secondary market. I will look again at the 710, perhaps today, as well as a Rukus.
Odd how a new knife's being delivered dull affects you - I wouldn't consider another BM for many years. When I did, it turned out to be dull, too. When I decided that I had to have a Skirmish or two, sharpness was secondary, as I had already re-edged my 15 month old EDC Spydie Native (S30V) - brave! Not necessary the Skirmishs were delivered sharp. Interestingly, I've never bought a Bark River, Boker Tree Brand, Buck, Kershaw, Marbles (old), Spyderco, or Vic SAK that wasn't a razor when new.
As an aside, I must state my appreciation for S30V - especially in an affordable platform. The Spydie Native from Wally World was a steal for <$40, although sadly dropped a year ago. I've used one for >2 yr EDC now. It did start getting warm one day, after ~15 months, as I cut down another large cb box. I re-edged it in short order with a Sharpmaker. An even better choice, perhaps, is the Buck #347 Vantage Pro - MSRP $75! It has contoured G10 over it's liner lock SS frame. A blade extension on the S30V blade permits 'flipper' opening - unassisted but very fast. That blade is the same size/shape as their #172 Mayo TNT - which is 4-5 times as much! Nice feel, too (But - the Native is no slouch!!). Just thought I'd mention them.
If it just has to be a BM... the Grip is a great place to start. What a horrid choice - a Benchmade! Super knives, when sharp. Expensive paperweights if dull. Try the 'feel' of as many of the different 'grips' as you can.
Stainz