I had to look up the E7495 and from what little I could find the specs are only guaranteed from 375 MHz to 2.7 GHz. For what I do it would be almost worthless as most of my work is in the HF, VHF, & UHF range. It doesn't show a calibrated signal generator nor audio generators. It seems to me to be a very highly specialized cell test gear. I will be looking forward to your testing.
I already mentioned the frequency range, and I suggested the E7495 only because the OP was asking for something up to 1.8GHz.
A bandwidth of up to 2.7GHz (E7495B, A variant is 2.5GHz) is also more than enough for lots of tasks as it covers a lot more than just cell phones (WiFi b/g/n, Bluetooth and other ISM stuff, ZigBee, DASH-7 and so on).
As to the E7495, the RF gen is certainly calibrated, and stability is pretty much excellent thanks to the built-in GPS reference. It doesn't have audio (but then the OP didn't ask for it!) but so don't standalone SAs. What it has is a Power Meter (requires an external measurement head, most Agilent standard types should do) which can be pretty handy. And unlike many other Comms Testers (i.e. Agilent 8960 Series 10) the E7495 is not "highly specialized", in fact unless you start one of the cell phone specific applications it looks and handles like any normal VSA, RF gen and Power Meter. The cable tester is useful as well, not only for profiling loss over the covered bandwidth but also for localizing defects (it can do 1-port and 2-port measurements). It can also measure Return Loss of cables, antennas and other RF parts. It runs Linux, and comes with USB, a PCMCIA and a CF slot, as well as a LAN interface, and Agilent offers some free program to control it remotely. The case is ruggedized for adverse environments and can certainly take some abuse.
The R&S CMU200 I also have is a bench/rack device, not a portable one like the E7495B. Mine does have audio (generator for up to 20 tones simultaneously plus THD and noise analyzer), the Reference OXCO option, two calibrated RF gens which also support various modulation types, a vector SA (10Mhz to 2.7GHz), a Power Meter (built-in), and aside from standard measurements can do a lot of other stuff. It also can be upgraded with various hardware options (i.e. I-Q analysis, Bluetooth analyzer).
Considering that the E7495B is from around 2010 I think it's a very good alternative to buying an old boat anchor like a HP 8568 which most certainly has long passed the zenith of its lifetime, and then invest even more money to keep it functioning. Don't get me wrong, these SAs were great in their days, but they are cheap because they are fragile and suck lots of power. This aside, even basic things like taking a screenshot is a pain in the arse with these old SAs. If you need the bandwidth (over 3GHz there aren't much alternatives if your budget is low) then it may be worth it, but certainly not if the requirement is 1.8Ghz of bandwidth.