Brad,
Have you owned a reflector, and are you a tinkerer? Reflectors, especially fast F/5 reflectors, require frequent tweaking to perform well, unlike your 80mm Firstscope. Besides, no matter WHAT scope you get, you are going to get better performance out of better eyepieces, period.
If you ARE a tinkerer, I agree that nothing will beat a good old newtonian reflector, inch for inch. If you are NOT a tinkerer, and just wanna get out there and look, I recommend getting some better eyepieces and saving your money to get a bigger Maksutov or ED refractor.
For eyepieces, I recommend the Burgess Optical/TMB Planetaries on the high powered end (available at a number of dealers), the Hyperion (or Orion Stratus) 24mm on the low powered end (especially in your Firstscope 80) and probably the 15mm Antares Elite Plossl in the middle (cheapest from Agena). These ep's will perform VERY well in your Firstscope, a 4" ED refractor, or a 6" reflector, for sure.
Check out this site ...
http://www.davidpaulgreen.com/tec.html
to put any possible eyepiece you might want to buy and determine how it will perform in your scope (or some other scope you're thinking of getting) You can replicate these formulas in Excel or some other spreadsheet, btw.
Good luck,
CDS