I'd use a Bugbuster except for two things; weight - they're heavier than I want sitting up top, and reticle lag when adjusting zero. I've read lots of reports from people saying the Leapers scopes are amazingly reliable for a lower priced scope, and I'm not in a position to say those reports are wrong. Perhaps I've just been unlucky with the two Leapers scopes I've tried. My son's 2240 regulated PCP carbine (HiPAC, modified CO2/HPA regulator from Robert Lane, tubular stock, 14" barrel, in .22") is really accurate for him out to at least 40 metres using a Bugbuster 6x scope. But getting the thing zeroed is a chore, as the reticle suffers from a buffering lag which means any adjustments to the reticle take anywhere from a few seconds to almost an hour to 'take.' Meaning I can be fussing with the scope trying to get the pellets on the mark and it's easy to over-adjust out of frustration as I am not sure the adjustment made is far enough... only to have the reticle jump at some random time and suddenly be well past where I intended to go.
I had use of a 3-9x Bugbuster for a couple of months two years ago, a scope a friend had bought but never used and was considering selling to me. I became so frustrated with trying to get it zeroed on two different PCP rifles that I gave up and sent it back to him. Again, once set it stayed set, worked beautifully. But getting it there was an exercise in frustration.
By comparison, adjustments to my Burris Rimfire 2-7x or Leupold lightweight 2-7x (both of which weigh far less than a Bugbuster while delivering vastly superior clarity and reticle quality) result in instantaneous changes in the crosshair location. A single click or 20 clicks doesn't make any difference, there simply isn't any lag time in adjustment. I can make an adjustment with these scopes, which are priced in the $300 to $400 range at a local shop, and my pellets will be in that new location relative to the crosshair on the next shot. I wish the budget-priced Bugbusters delivered at least something close to that level of responsiveness. I can forgive a lot in optical quality (and Leapers glass isn't bad, at all, it's just not nearly so nice as looking through Leupold or especially Burris glass), but when a scope gets in my way by taking unpredictable amounts of time to adjust I get very frustrated.
Another point of comparison for me is two ancient Weaver 4x scopes, one a B4 from the 1950's, the other a D4 from the 1960's. Both suffer from a very slight reticle lag, either due to age or just the expected level of performance. But both will show the newly adjusted zero within a minute or so of clicking the turrets. I've had other scopes with reticle lag - a very compact RWS 4x takes between a minute and 5 minutes to show a change, though banging on it with my hand speeds it along. A generic Chinese 3x 4x-32 AIM scope is similar, needing a bit of a bump to get it to change immediately but otherwise shifting on its own within a few minutes. The Bugbusters just seem especially stubborn, at least in the two examples I've tested.
