The 4200 has always been a very good scope in regard to the optic quality, but in my opinion, has been let down by build quality and also sheer size. The old 6-24 was a massive 17" long. If you were after a compact high mag scope, then the Bushnell was out of the running. The build quality was not a big issue, but compared to the older Burris Sig' series and definitely by the superb build quality of the Leupold, the 4200 was just not up there.
I purchased a 6-24 x 40 (426242P) for my CZ 17 HMR as I wanted the higher mag with a low profile.
Initially I was disappointed as the scope comes in a much smaller box than the old 4200 and did not include a sunshade.
Picking the scope up it was obvious that the build quality was superb and did have a very solid feel. The weight was down to a paultry 500 grams, so very light for the spec. The 13" length made the scope extremely compact for the spec and the lack of the front bell parallax meant that the scope easily mounted on a set of low mounts.
I've always found the optics on Bushnells amazing for the price (their Scopechief range is still in my opinion one of the best set of scopes ever made) and this was as good or better than anything I had seen from them before. Absolutely stunning. Compared to a Zeiss Conquest 4.5-14 x 44, the Bushnell was brighter and clearer on a target in twilight and useable in daker conditions than the zeiss.
The side PX is great and more suited to all applications than the objective PX type, especially on longer scopes whilst hunting. The movement is positive and just the right amount of friction to allow adjustment with gloves on.
Performance wise, the PX was accurate and a buddy of mine has found that he can range find between 90 and 100 yards consistantly. I will PX down to about 23 yards on 24 mag and down to 10 on 12.
The mildot reticule is okay, but I personally don't like them. The scope on 12 mag gives true mildot measurements, this halves as you get to 24 mag. According to my buddy, this gives approximately 2 mildots at 200 yards for an HMR if zeroed at 100.

Apart from the Mildot reticle, the scope has one area that makes it fall from my "ultimate" scope position. That being the Field Of View.
In most applications, this will not detract from it's superb abilities, however, I mounted this to my 243 for a lamping session, and the FOV issue became apparent. Sotting a fox in the lamp and then in the scope was not proving very easy, even on a low mag setting of 6 the FOV was restrictive. Comapred to the Zeiss 4.4-14, the Bushnell was harder to use.
If using for closer range lamping on a rimfire, and normal day use, I think the 4200 42-6242 P is fantastic given the price. If you wanted an all round day/night scope for a fullbore 200 yard scope, then I think there are better scopes around.